HEATING AND AIR CONDITIONING - Jeepstock Jeep/1998_TJ...air conditioning, heating, and ventilating capabilities in a single unit housing mounted under the instru-ment panel. On heater-only

TJ HEATING AND AIR CONDITIONING 24 - 1

HEATING AND AIR CONDITIONING

CONTENTS

page

GENERAL INFORMATIONHEATER AND AIR CONDITIONER CONTROL . . . 2HEATER AND AIR CONDITIONER . . . . . . . . . . . . 2SERVICE WARNINGS AND PRECAUTIONS . . . . 3

DESCRIPTION AND OPERATIONACCUMULATOR . . . . . . . . . . . . . . . . . . . . . . . . . 4BLOWER MOTOR RELAY . . . . . . . . . . . . . . . . . . 5BLOWER MOTOR RESISTOR . . . . . . . . . . . . . . . 5BLOWER MOTOR SWITCH . . . . . . . . . . . . . . . . . 5BLOWER MOTOR . . . . . . . . . . . . . . . . . . . . . . . . 5COMPRESSOR CLUTCH RELAY . . . . . . . . . . . . . 6COMPRESSOR CLUTCH . . . . . . . . . . . . . . . . . . . 6COMPRESSOR . . . . . . . . . . . . . . . . . . . . . . . . . . 5CONDENSER . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6EVAPORATOR COIL . . . . . . . . . . . . . . . . . . . . . . 6FIXED ORIFICE TUBE . . . . . . . . . . . . . . . . . . . . . 7HEATER CORE . . . . . . . . . . . . . . . . . . . . . . . . . . 7HIGH PRESSURE CUT-OFF SWITCH . . . . . . . . . 7HIGH PRESSURE RELIEF VALVE . . . . . . . . . . . . 7LOW PRESSURE CYCLING CLUTCH SWITCH . . 7REFRIGERANT LINE COUPLER . . . . . . . . . . . . . 8REFRIGERANT LINE . . . . . . . . . . . . . . . . . . . . . . 8REFRIGERANT OIL . . . . . . . . . . . . . . . . . . . . . . . 9REFRIGERANT SYSTEM SERVICE

EQUIPMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . 9REFRIGERANT SYSTEM SERVICE PORT . . . . . 10REFRIGERANT . . . . . . . . . . . . . . . . . . . . . . . . . . 8VACUUM CHECK VALVE . . . . . . . . . . . . . . . . . . 10VACUUM RESERVOIR . . . . . . . . . . . . . . . . . . . 10

DIAGNOSIS AND TESTINGA/C PERFORMANCE . . . . . . . . . . . . . . . . . . . . . 10BLOWER MOTOR RELAY . . . . . . . . . . . . . . . . . 18BLOWER MOTOR RESISTOR . . . . . . . . . . . . . . 19BLOWER MOTOR SWITCH . . . . . . . . . . . . . . . . 19BLOWER MOTOR . . . . . . . . . . . . . . . . . . . . . . . 18COMPRESSOR CLUTCH COIL . . . . . . . . . . . . . 20COMPRESSOR CLUTCH RELAY . . . . . . . . . . . . 21COMPRESSOR . . . . . . . . . . . . . . . . . . . . . . . . . 20

page

HEATER PERFORMANCE . . . . . . . . . . . . . . . . . 14HIGH PRESSURE CUT-OFF SWITCH . . . . . . . . 21LOW PRESSURE CYCLING CLUTCH SWITCH . 21REFRIGERANT SYSTEM LEAKS . . . . . . . . . . . . 22VACUUM SYSTEM . . . . . . . . . . . . . . . . . . . . . . 14

SERVICE PROCEDURESREFRIGERANT OIL LEVEL . . . . . . . . . . . . . . . . 23REFRIGERANT RECOVERY . . . . . . . . . . . . . . . . 22REFRIGERANT SYSTEM CHARGE . . . . . . . . . . 23REFRIGERANT SYSTEM EVACUATE . . . . . . . . . 22

REMOVAL AND INSTALLATIONACCUMULATOR . . . . . . . . . . . . . . . . . . . . . . . . 31BLOWER MOTOR RELAY . . . . . . . . . . . . . . . . . 37BLOWER MOTOR RESISTOR . . . . . . . . . . . . . . 37BLOWER MOTOR SWITCH . . . . . . . . . . . . . . . . 35BLOWER MOTOR . . . . . . . . . . . . . . . . . . . . . . . 34COMPRESSOR CLUTCH RELAY . . . . . . . . . . . . 29COMPRESSOR CLUTCH . . . . . . . . . . . . . . . . . . 26COMPRESSOR . . . . . . . . . . . . . . . . . . . . . . . . . 26CONDENSER . . . . . . . . . . . . . . . . . . . . . . . . . . . 32DUCTS AND OUTLETS . . . . . . . . . . . . . . . . . . . 44EVAPORATOR COIL . . . . . . . . . . . . . . . . . . . . . 43FIXED ORIFICE TUBE . . . . . . . . . . . . . . . . . . . . 30HEATER CORE . . . . . . . . . . . . . . . . . . . . . . . . . 44HEATER-A/C CONTROL . . . . . . . . . . . . . . . . . . 34HEATER-A/C HOUSING DOOR . . . . . . . . . . . . . 42HEATER-A/C HOUSING . . . . . . . . . . . . . . . . . . . 39HIGH PRESSURE CUT-OFF SWITCH . . . . . . . . 24KICK COVER . . . . . . . . . . . . . . . . . . . . . . . . . . . 37LIQUID LINE . . . . . . . . . . . . . . . . . . . . . . . . . . . 29LOW PRESSURE CYCLING CLUTCH SWITCH . 31MODE DOOR VACUUM ACTUATOR . . . . . . . . . 38REFRIGERANT LINE COUPLER . . . . . . . . . . . . 23SUCTION AND DISCHARGE LINE . . . . . . . . . . 25TEMPERATURE CONTROL CABLE . . . . . . . . . . 36VACUUM CHECK VALVE . . . . . . . . . . . . . . . . . . 33VACUUM RESERVOIR . . . . . . . . . . . . . . . . . . . 34

24 - 2 HEATING AND AIR CONDITIONING TJ

GENERAL INFORMATION

HEATER AND AIR CONDITIONERAll vehicles are equipped with a common heater-

A/C housing assembly (Fig. 1). The system combinesair conditioning, heating, and ventilating capabilitiesin a single unit housing mounted under the instru-ment panel. On heater-only systems, the evaporatorcoil and recirculating air door are omitted from thehousing.

Outside fresh air enters the vehicle through thecowl top opening at the base of the windshield, andpasses through a plenum chamber to the heater-A/Csystem blower housing. Air flow velocity can then beadjusted with the blower motor speed selector switchon the heater-A/C control panel. The air intake open-ings must be kept free of snow, ice, leaves, and otherobstructions for the heater-A/C system to receive asufficient volume of outside air.

It is also important to keep the air intake openingsclear of debris because leaf particles and other debristhat is small enough to pass through the cowl ple-num screen can accumulate within the heater-A/Chousing. The closed, warm, damp and dark environ-ment created within the heater-A/C housing is idealfor the growth of certain molds, mildews and otherfungi. Any accumulation of decaying plant matterprovides an additional food source for fungal spores,which enter the housing with the fresh air. Excessdebris, as well as objectionable odors created bydecaying plant matter and growing fungi can be dis-charged into the passenger compartment duringheater-A/C system operation.

The heater and optional air conditioner are blend-air type systems. In a blend-air system, a blend-airdoor controls the amount of unconditioned air (orcooled air from the evaporator on models with air

Fig. 1 Common Blend-Air Heater-Air ConditionerSystem - Typical

conditioning) that is allowed to flow through, oraround, the heater core. A temperature control leveron the heater-A/C control panel determines the dis-charge air temperature by moving a cable, whichoperates the blend-air door. This allows an almostimmediate manual control of the output air tempera-ture of the system.

The mode control lever on the heater-only or heat-er-A/C control panel is used to direct the conditionedair to the selected system outlets. Both mode controlswitches use engine vacuum to control the modedoors, which are operated by vacuum actuatormotors.

On air conditioned vehicles, the outside air intakecan be shut off by selecting the Recirculation Modewith the mode control lever. This will operate a vac-uum actuated recirculating air door that closes offthe outside fresh air intake and recirculates the airthat is already inside the vehicle.

The optional air conditioner for all models isdesigned for the use of non-CFC, R-134a refrigerant.The air conditioning system has an evaporator to cooland dehumidify the incoming air prior to blending itwith the heated air. This system uses a fixed orificetube in the liquid line near the condenser outlet tubeto meter refrigerant flow to the evaporator coil. Tomaintain minimum evaporator temperature, a fixedsetting pressure switch on the accumulator cycles thecompressor clutch.

HEATER AND AIR CONDITIONER CONTROLBoth the heater-only and heater-A/C systems use a

combination of mechanical, electrical, and vacuumcontrols. These controls provide the vehicle operatorwith a number of setting options to help control theclimate and comfort within the vehicle. Refer to theowner’s manual for more information on the sug-gested operation and use of these controls.

The heater-only or heater-A/C control panel islocated in the instrument panel center bezel belowthe radio and above the accessory switch bezel andash receiver. The control panel contains a sliding-type temperature control knob, a sliding-type modecontrol switch knob, and a rotary-type blower motorspeed switch knob.

The heater-only or heater-A/C control panel cannotbe repaired. If faulty or damaged, the entire unitmust be replaced. The illumination lamps, the blowermotor switch, and the control knobs are available forservice replacement.


GENERAL INFORMATION (Continued)

SERVICE WARNINGS AND PRECAUTIONS

WARNING:• THE AIR CONDITIONING SYSTEM CONTAINS

REFRIGERANT UNDER HIGH PRESSURE. SEVEREPERSONAL INJURY MAY RESULT FROM IMPROPERSERVICE PROCEDURES. REPAIRS SHOULD ONLYBE PERFORMED BY QUALIFIED SERVICE PERSON-NEL.

• AVOID BREATHING THE REFRIGERANT ANDREFRIGERANT OIL VAPOR OR MIST. EXPOSUREMAY IRRITATE THE EYES, NOSE, AND/OR THROAT.WEAR EYE PROTECTION WHEN SERVICING THEAIR CONDITIONING REFRIGERANT SYSTEM. SERI-OUS EYE INJURY CAN RESULT FROM DIRECTCONTACT WITH THE REFRIGERANT. IF EYE CON-TACT OCCURS, SEEK MEDICAL ATTENTION IMME-DIATELY.

• DO NOT EXPOSE THE REFRIGERANT TOOPEN FLAME. POISONOUS GAS IS CREATEDWHEN REFRIGERANT IS BURNED. AN ELEC-TRONIC LEAK DETECTOR IS RECOMMENDED.

• IF ACCIDENTAL SYSTEM DISCHARGEOCCURS, VENTILATE THE WORK AREA BEFORERESUMING SERVICE. LARGE AMOUNTS OFREFRIGERANT RELEASED IN A CLOSED WORKAREA WILL DISPLACE THE OXYGEN AND CAUSESUFFOCATION.

• THE EVAPORATION RATE OF R-134a REFRIG-ERANT AT AVERAGE TEMPERATURE AND ALTI-TUDE IS EXTREMELY HIGH. AS A RESULT,ANYTHING THAT COMES IN CONTACT WITH THEREFRIGERANT WILL FREEZE. ALWAYS PROTECTTHE SKIN OR DELICATE OBJECTS FROM DIRECTCONTACT WITH THE REFRIGERANT.

• THE R-134a SERVICE EQUIPMENT OR THEVEHICLE REFRIGERANT SYSTEM SHOULD NOT BEPRESSURE TESTED OR LEAK TESTED WITH COM-PRESSED AIR. SOME MIXTURES OF AIR ANDR-134a HAVE BEEN SHOWN TO BE COMBUSTIBLEAT ELEVATED PRESSURES. THESE MIXTURES AREPOTENTIALLY DANGEROUS, AND MAY RESULT INFIRE OR EXPLOSION CAUSING INJURY OR PROP-ERTY DAMAGE.

CAUTION:• Liquid refrigerant is corrosive to metal sur-

faces. Follow the operating instructions suppliedwith the service equipment being used.

• Never add R-12 to a refrigerant systemdesigned to use R-134a. Damage to the system willresult.

• R-12 refrigerant oil must not be mixed withR-134a refrigerant oil. They are not compatible.

• Do not use R-12 equipment or parts on theR-134a system. Damage to the system will result.

• Do not overcharge the refrigerant system. Thiswill cause excessive compressor head pressureand can cause noise and system failure.

• Recover the refrigerant before opening any fit-ting or connection. Open the fittings with caution,even after the system has been discharged. Neveropen or loosen a connection before recovering therefrigerant.

• The refrigerant system must always be evacu-ated before charging.

• Do not open the refrigerant system or uncap areplacement component until you are ready to ser-vice the system. This will prevent contamination inthe system.

• Before disconnecting a component, clean theoutside of the fittings thoroughly to prevent con-tamination from entering the refrigerant system.

• Immediately after disconnecting a componentfrom the refrigerant system, seal the open fittingswith a cap or plug.

• Before connecting an open refrigerant fitting,always install a new seal or gasket. Coat the fittingand seal with clean refrigerant oil before connect-ing.

• Do not remove the sealing caps from a replace-ment component until it is to be installed.

• When installing a refrigerant line, avoid sharpbends that may restrict refrigerant flow. Position therefrigerant lines away from exhaust system compo-nents or any sharp edges, which may damage theline.

• Tighten refrigerant fittings only to the specifiedtorque. The aluminum fittings used in the refriger-ant system will not tolerate overtightening.

• When disconnecting a refrigerant fitting, use awrench on both halves of the fitting. This will pre-vent twisting of the refrigerant lines or tubes.

• Refrigerant oil will absorb moisture from theatmosphere if left uncapped. Do not open a con-tainer of refrigerant oil until you are ready to use it.Replace the cap on the oil container immediatelyafter using. Store refrigerant oil only in a clean, air-tight, and moisture-free container.

• Keep service tools and the work area clean.Contamination of the refrigerant system throughcareless work habits must be avoided.

COOLING SYSTEM REQUIREMENTSTo maintain the performance level of the heating-

air conditioning system, the engine cooling systemmust be properly maintained. The use of a bugscreen is not recommended. Any obstructions in frontof the radiator or condenser will reduce the perfor-mance of the air conditioning and engine cooling sys-tems.


GENERAL INFORMATION (Continued)

The engine cooling system includes the heater coreand the heater hoses. Refer to Group 7 - Cooling Sys-tem for more information before the opening of, orattempting any service to the engine cooling system.

REFRIGERANT HOSES/LINES/TUBESPRECAUTIONS

Kinks or sharp bends in the refrigerant plumbingwill reduce the capacity of the entire system. Highpressures are produced in the system when it is oper-ating. Extreme care must be exercised to make surethat all refrigerant system connections are pressuretight.

A good rule for the flexible hose refrigerant lines isto keep the radius of all bends at least ten times thediameter of the hose. Sharp bends will reduce theflow of refrigerant. The flexible hose lines should berouted so they are at least 80 millimeters (3 inches)from the exhaust manifold. It is a good practice toinspect all flexible refrigerant system hose lines atleast once a year to make sure they are in good con-dition and properly routed.

There are two types of refrigerant fittings:• All fittings with O-rings need to be coated with

refrigerant oil before installation. Use only O-ringsapproved for use with R-134a refrigerant. Failure todo so may result in a leak.

• Unified plumbing connections with aluminumgaskets cannot be serviced with O-rings. The gasketsare not reusable and new gaskets do not requirelubrication before installing.

Using the proper tools when making a refrigerantplumbing connection is very important. Impropertools or improper use of the tools can damage therefrigerant fittings. Always use two wrenches whenloosening or tightening tube fittings. Use one wrenchto hold one side of the connection stationary, whileloosening or tightening the other side of the connec-tion with a second wrench.

The refrigerant must be recovered completely fromthe system before opening any fitting or connection.Open the fittings with caution, even after the refrig-erant has been recovered. If any pressure is noticedas a fitting is loosened, tighten the fitting andrecover the refrigerant from the system again.

Do not discharge refrigerant into the atmosphere.Use an R-134a refrigerant recovery/recycling devicethat meets SAE Standard J2210.

The refrigerant system will remain chemically sta-ble as long as pure, moisture-free R-134a refrigerantand refrigerant oil is used. Dirt, moisture, or air canupset this chemical stability. Operational troubles orserious damage can occur if foreign material ispresent in the refrigerant system.

When it is necessary to open the refrigerant sys-tem, have everything needed to service the systemready. The refrigerant system should not be left open

to the atmosphere any longer than necessary. Cap orplug all lines and fittings as soon as they are openedto prevent the entrance of dirt and moisture. All linesand components in parts stock should be capped orsealed until they are to be installed.

All tools, including the refrigerant recycling equip-ment, the manifold gauge set, and test hoses shouldbe kept clean and dry. All tools and equipment mustbe designed for R-134a refrigerant.

DESCRIPTION AND OPERATION

ACCUMULATORThe accumulator is mounted in the engine com-

partment between the evaporator coil outlet tube andthe compressor inlet. Refrigerant enters the accumu-lator canister as a low pressure vapor through theinlet tube.

Any liquid, oil-laden refrigerant falls to the bottomof the canister, which acts as a separator. A desiccantbag is mounted inside the accumulator canister toabsorb any moisture which may have entered andbecome trapped within the refrigerant system (Fig.2).

Fig. 2 Accumulator - Typical


DESCRIPTION AND OPERATION (Continued)

BLOWER MOTORThe blower motor and blower wheel are located in

the passenger side end of the heater-A/C housing,below the glove box. The blower motor controls thevelocity of air flowing through the heater-A/C hous-ing by spinning a squirrel cage-type blower wheelwithin the housing at the selected speed. The blowermotor and wheel can be removed through an openingin the engine compartment side of the dash panelwithout heater-A/C housing removal.

The blower motor will only operate when the igni-tion switch is in the On position, and the heater-A/Cmode control switch knob is in any position, exceptOff. The blower motor receives a ground feed at alltimes. The blower motor battery feed circuit is pro-tected by a fuse in the fuseblock module for allblower speeds except high. The high speed batteryfeed circuit is protected by a fuse in the Power Dis-tribution Center (PDC). Blower motor speed is con-trolled by regulating the battery feed through theblower motor switch, blower motor resistor, and ablower motor relay.

The blower motor and blower motor wheel cannotbe repaired and, if faulty or damaged, they must bereplaced as a unit.

BLOWER MOTOR RELAYThe blower motor relay is a International Stan-

dards Organization (ISO)-type relay. The relay is aelectromechanical device that switches battery cur-rent to the blower motor.

When the blower motor switch is in any positionexcept high, the blower motor relay is de-energizedand provides battery feed to the blower motor from afuse in the fuseblock module through the blowermotor resistor. When the blower motor switch is inthe high speed position, the blower motor relay isenergized and provides battery feed to the blowermotor from a fuse in the Power Distribution Center(PDC), bypassing the remainder of the blower motorfeed circuit.

The blower motor relay coil is controlled by a volt-age signal from the blower motor switch. See theDiagnosis and Testing section of this group for moreinformation on the operation of the blower motorrelay.

The blower motor relay is installed in a connectorlocated near the passenger side outboard end of theheater-A/C housing in the passenger compartment,next to the heater-A/C wire harness connector.

The blower motor relay cannot be repaired and, iffaulty or damaged, it must be replaced.

BLOWER MOTOR RESISTORThe blower motor resistor is mounted to the bot-

tom of the heater-A/C housing on the passenger side

of the vehicle under the instrument panel. It can beaccessed for service by removing the heater-A/Chousing kick cover.

The resistor has multiple resistor wires, each ofwhich reduce the current flow to the blower motor, tochange the blower motor speed. The blower motorswitch directs battery current to the correct resistorwire to obtain the selected speed. When the highestblower motor speed is selected, the blower motorrelay connects the blower motor directly to batterycurrent, bypassing the blower motor resistor.

The blower motor resistor cannot be repaired and,if faulty or damaged, it must be replaced.

BLOWER MOTOR SWITCHThe heater-only or heater-A/C blower motor is con-

trolled by a four position rotary-type blower motorswitch, mounted in the heater-A/C control panel. Theswitch allows the selection of one of four blowermotor speeds, but can only be turned off by selectingthe Off position with the heater-A/C mode controlswitch.

The blower motor switch receives ignition-switchedbattery current through the mode control switch froma fuse in the fuseblock module. The blower motorswitch directs the battery current to the blowermotor resistor, or to the blower motor relay, asrequired to achieve the selected blower motor speed.

The blower motor switch cannot be repaired and, iffaulty or damaged, it must be replaced. The blowermotor switch knob is available for service replace-ment.

COMPRESSORThe air conditioning system uses a Sanden

SD7H15 seven cylinder, reciprocating wobble plate-type compressor on all models. This compressor has afixed displacement of 150 cubic centimeters (9.375cubic inches), and has both the suction and dischargeports located on the cylinder head. A label identifyingthe use of R-134a refrigerant is located on the com-pressor.

The compressor is driven by the engine through anelectric clutch, drive pulley and belt arrangement.The compressor is lubricated by refrigerant oil that iscirculated throughout the refrigerant system with therefrigerant.

The compressor draws in low-pressure refrigerantvapor from the evaporator through its suction port. Itthen compresses the refrigerant into a high-pressure,high-temperature refrigerant vapor, which is thenpumped to the condenser through the compressor dis-charge port.

The compressor cannot be repaired. If faulty ordamaged, the entire compressor assembly must be



replaced. The compressor clutch, pulley and clutchcoil are available for service.

COMPRESSOR CLUTCHThe compressor clutch assembly consists of a sta-

tionary electromagnetic coil, a hub bearing and pul-ley assembly, and a clutch plate (Fig. 3). Theelectromagnetic coil unit and the hub bearing andpulley assembly are each retained on the nose of thecompressor front housing with snap rings. The clutchplate is keyed to the compressor shaft and securedwith a nut.

These components provide the means to engageand disengage the compressor from the engine ser-pentine accessory drive belt. When the clutch coil isenergized, it magnetically draws the clutch into con-tact with the pulley and drives the compressor shaft.When the coil is not energized, the pulley freewheelson the clutch hub bearing, which is part of the pulley.The compressor clutch and coil are the only servicedparts on the compressor.

The compressor clutch engagement is controlled byseveral components: the heater-A/C mode controlswitch, the low pressure cycling clutch switch, thehigh pressure cut-off switch, the compressor clutchrelay, and the Powertrain Control Module (PCM).The PCM may delay compressor clutch engagementfor up to thirty seconds. Refer to Group 14 - FuelSystem for more information on the PCM controls.

COMPRESSOR CLUTCH RELAYThe compressor clutch relay is a International

Standards Organization (ISO) micro-relay. The termi-nal designations and functions are the same as a con-ventional ISO relay. However, the micro-relayterminal orientation (footprint) is different, currentcapacity is lower, and the relay case dimensions aresmaller than those of the conventional ISO relay.

The compressor clutch relay is a electromechanicaldevice that switches battery current to the compres-

Fig. 3 Compressor Clutch

sor clutch coil when the Powertrain Control Module(PCM) grounds the coil side of the relay. The PCMresponds to inputs from the heater-A/C mode controlswitch, the low pressure cycling clutch switch, andthe high pressure cut-off switch. See the Diagnosisand Testing section of this group for more informa-tion on the operation of the compressor clutch relay.

The compressor clutch relay is located in the PowerDistribution Center (PDC) in the engine compart-ment. Refer to the PDC label for relay identificationand location.

The compressor clutch relay cannot be repairedand, if faulty or damaged, it must be replaced.

CONDENSERThe condenser is located in the air flow in front of

the engine cooling radiator. The condenser is a heatexchanger that allows the high-pressure refrigerantgas being discharged by the compressor to give up itsheat to the air passing over the condenser fins. Whenthe refrigerant gas gives up its heat, it condenses.When the refrigerant leaves the condenser, it hasbecome a high-pressure liquid refrigerant.

The volume of air flowing over the condenser finsis critical to the proper cooling performance of the airconditioning system. Therefore, it is important thatthere are no objects placed in front of the radiatorgrille openings in the front of the vehicle or foreignmaterial on the condenser fins that might obstructproper air flow. Also, any factory-installed air seals orshrouds must be properly reinstalled following radia-tor or condenser service.

The condenser cannot be repaired and, if faulty ordamaged, it must be replaced.

EVAPORATOR COILThe evaporator coil is located in the heater-A/C

housing, under the instrument panel. The evaporatorcoil is positioned in the heater-A/C housing so thatall air that enters the housing must pass over thefins of the evaporator before it is distributed throughthe system ducts and outlets. However, air passingover the evaporator coil fins will only be conditionedwhen the compressor is engaged and circulatingrefrigerant through the evaporator coil tubes.

Refrigerant enters the evaporator from the fixedorifice tube as a low-temperature, low-pressure liq-uid. As air flows over the fins of the evaporator, thehumidity in the air condenses on the fins, and theheat from the air is absorbed by the refrigerant. Heatabsorption causes the refrigerant to boil and vapor-ize. The refrigerant becomes a low-pressure gasbefore it leaves the evaporator.

The evaporator coil cannot be repaired and, iffaulty or damaged, it must be replaced.



FIXED ORIFICE TUBEThe fixed orifice tube is installed in the liquid line

between the outlet of the condenser and the inlet ofthe evaporator. The fixed orifice tube is located in theend of the liquid line that is closest to the condenseroutlet tube.

The inlet end of the fixed orifice tube has a nylonmesh filter screen, which filters the refrigerant andhelps to reduce the potential for blockage of themetering orifice by refrigerant system contaminants(Fig. 4). The outlet end of the tube has a nylon meshdiffuser screen. The O-rings on the plastic body ofthe fixed orifice tube seal the tube to the inside ofthe liquid line and prevent the refrigerant frombypassing the fixed metering orifice.

The fixed orifice tube is used to meter the flow ofliquid refrigerant into the evaporator coil. The high-pressure liquid refrigerant from the condenserexpands into a low-pressure liquid as it passesthrough the metering orifice and diffuser screen ofthe fixed orifice tube.

The fixed orifice tube cannot be repaired and, iffaulty or plugged, it must be replaced.

HEATER COREThe heater core is located in the heater-A/C hous-

ing, under the instrument panel. It is a heatexchanger made of rows of tubes and fins. Enginecoolant is circulated through heater hoses to theheater core at all times. As the coolant flows throughthe heater core, heat removed from the engine istransferred to the heater core fins and tubes.

Air directed through the heater core picks up theheat from the heater core fins. The blend air doorallows control of the heater output air temperatureby controlling how much of the air flowing throughthe heater-A/C housing is directed through theheater core. The blower motor speed controls the vol-ume of air flowing through the heater-A/C housing.

The heater core cannot be repaired and, if faulty ordamaged, it must be replaced. Refer to Group 7 -Cooling System for more information on the enginecooling system, the engine coolant and the heaterhoses.

Fig. 4 Fixed Orifice Tube - Typical

HIGH PRESSURE CUT-OFF SWITCHThe high pressure cut-off switch is located on the

discharge line near the compressor. The switch isscrewed onto a discharge line fitting that contains aSchrader-type valve, which allows the switch to beserviced without discharging the refrigerant system.The discharge line fitting is equipped with an O-ringto seal the switch connection.

The high pressure cut-off switch is connected inseries electrically with the low pressure cyclingclutch switch between ground and the PowertrainControl Module (PCM). The switch contacts open andclose causing the PCM to turn the compressor clutchon and off. This prevents compressor operation whenthe discharge line pressure approaches high levels.

The high pressure cut-off switch contacts are openwhen the discharge line pressure rises above 3100 to3375 kPa (450 to 490 psi). The switch contacts willclose when the discharge line pressure drops to 1860to 2275 kPa (270 to 330 psi).

The high pressure cut-off switch is a factory-cali-brated unit. The switch cannot be adjusted orrepaired and, if faulty or damaged, it must bereplaced.

HIGH PRESSURE RELIEF VALVEA high pressure relief valve is located on the com-

pressor cylinder head, which is at the rear of thecompressor. This mechanical valve is designed tovent refrigerant from the system to protect againstdamage to the compressor and other system compo-nents, caused by condenser air flow restriction or anovercharge of refrigerant.

The high pressure relief valve vents the systemwhen a discharge pressure of 3445 to 4135 kPa (500to 600 psi) or above is reached. The valve closeswhen a minimum discharge pressure of 2756 kPa(400 psi) is reached.

The high pressure relief valve vents only enoughrefrigerant to reduce the system pressure, and thenre-seats itself. The majority of the refrigerant is con-served in the system. If the valve vents refrigerant, itdoes not mean that the valve is faulty.

The high pressure relief valve is a factory-cali-brated unit. The valve cannot be adjusted orrepaired, and must not be removed or otherwise dis-turbed. The valve is only serviced as a part of thecompressor assembly.

LOW PRESSURE CYCLING CLUTCH SWITCHThe low pressure cycling clutch switch is located

on the top of the accumulator. The switch is screwedonto an accumulator fitting that contains a Schrader-type valve, which allows the switch to be servicedwithout discharging the refrigerant system. The



accumulator fitting is equipped with an O-ring toseal the switch connection.

The low pressure cycling clutch switch is connectedin series electrically with the high pressure cut-offswitch, between ground and the Powertrain ControlModule (PCM). The switch contacts open and closecausing the PCM to turn the compressor clutch onand off. This regulates the refrigerant system pres-sure and controls evaporator temperature. Control-ling the evaporator temperature prevents condensatewater on the evaporator fins from freezing andobstructing air conditioning system air flow.

The low pressure cycling clutch switch contacts areopen when the suction pressure is approximately 141kPa (20.5 psi) or lower. The switch contacts will closewhen the suction pressure rises to approximately 234to 262 kPa (34 to 38 psi) or above. Lower ambienttemperatures, below approximately -1° C (30° F), willalso cause the switch contacts to open. This is due tothe pressure/temperature relationship of the refriger-ant in the system.

The low pressure cycling clutch switch is a factory-calibrated unit. It cannot be adjusted or repairedand, if faulty or damaged, it must be replaced.

REFRIGERANTThe refrigerant used in this air conditioning sys-

tem is a HydroFluoroCarbon (HFC), type R-134a.Unlike R-12, which is a ChloroFluoroCarbon (CFC),R-134a refrigerant does not contain ozone-depletingchlorine. R-134a refrigerant is a non-toxic, non-flam-mable, clear, and colorless liquefied gas.

Even though R-134a does not contain chlorine, itmust be reclaimed and recycled just like CFC-typerefrigerants. This is because R-134a is a greenhousegas and can contribute to global warming.

R-134a refrigerant is not compatible with R-12refrigerant in an air conditioning system. Even asmall amount of R-12 added to an R-134a refrigerantsystem will cause compressor failure, refrigerant oilsludge or poor air conditioning system performance.In addition, the PolyAlkylene Glycol (PAG) syntheticrefrigerant oils used in an R-134a refrigerant systemare not compatible with the mineral-based refriger-ant oils used in an R-12 refrigerant system.

R-134a refrigerant system service ports, servicetool couplers and refrigerant dispensing bottles haveall been designed with unique fittings to ensure thatan R-134a system is not accidentally contaminatedwith the wrong refrigerant (R-12). There are alsolabels posted in the engine compartment of the vehi-cle and on the compressor identifying to service tech-nicians that the air conditioning system is equippedwith R-134a.

REFRIGERANT LINEThe refrigerant lines and hoses are used to carry

the refrigerant between the various air conditioningsystem components. A barrier hose design with anylon tube inner hose liner is used for the R-134a airconditioning system on this vehicle. This nylon linerhelps to further contain the R-134a refrigerant,which has a smaller molecular structure than R-12refrigerant. The ends of the refrigerant hoses aremade from lightweight aluminum, and use braze-lessfittings.

Any kinks or sharp bends in the refrigerant plumb-ing will reduce the capacity of the entire air condi-tioning system. Kinks and sharp bends reduce theflow of refrigerant in the system. A good rule for theflexible hose refrigerant lines is to keep the radius ofall bends at least ten times the diameter of the hose.In addition, the flexible hose refrigerant lines shouldbe routed so they are at least 80 millimeters (3inches) from the exhaust manifold.

High pressures are produced in the refrigerant sys-tem when the air conditioning compressor is operat-ing. Extreme care must be exercised to make surethat each of the refrigerant system connections ispressure-tight and leak free. It is a good practice toinspect all flexible hose refrigerant lines at least oncea year to make sure they are in good condition andproperly routed.

The refrigerant lines and hoses cannot be repairedand, if faulty or damaged, they must be replaced.

REFRIGERANT LINE COUPLERSpring-lock type refrigerant line couplers are used

to connect many of the refrigerant lines and othercomponents to the refrigerant system. These couplersrequire a special tool for disengaging the two couplerhalves.

The spring-lock coupler is held together by a garterspring inside a circular cage on the male half of thefitting (Fig. 5). When the two coupler halves are con-nected, the flared end of the female fitting slipsbehind the garter spring inside the cage on the malefitting. The garter spring and cage prevent the flaredend of the female fitting from pulling out of the cage.

Two O-rings on the male half of the fitting areused to seal the connection. These O-rings are com-patible with R-134a refrigerant and must be replacedwith O-rings made of the same material.

Secondary clips are installed over the two con-nected coupler halves at the factory for added blowoffprotection. In addition, a plastic ring is used at thefactory as a visual indicator to confirm that thesecouplers are connected. After the coupler is con-nected, the plastic indicator ring is no longer needed;however, it will remain on the refrigerant line nearthe coupler cage.



REFRIGERANT OILThe refrigerant oil used in R-134a refrigerant sys-

tems is a synthetic-based, PolyAlkylene Glycol (PAG),wax-free lubricant. Mineral-based R-12 refrigerantoils are not compatible with PAG oils, and shouldnever be introduced to an R-134a refrigerant system.

There are different PAG oils available, and eachcontains a different additive package. The SD7H15compressor used in this vehicle is designed to use anSP-20 PAG refrigerant oil. Use only refrigerant oil ofthis same type to service the refrigerant system.

After performing any refrigerant recovery or recy-cling operation, always replenish the refrigerant sys-tem with the same amount of the recommendedrefrigerant oil as was removed. Too little refrigerantoil can cause compressor damage, and too much canreduce air conditioning system performance.

PAG refrigerant oil is much more hygroscopic thanmineral oil, and will absorb any moisture it comesinto contact with, even moisture in the air. The PAGoil container should always be kept tightly cappeduntil it is ready to be used. After use, recap the oilcontainer immediately to prevent moisture contami-nation.

REFRIGERANT SYSTEM SERVICE EQUIPMENT

WARNING: EYE PROTECTION MUST BE WORNWHEN SERVICING AN AIR CONDITIONING REFRIG-ERANT SYSTEM. TURN OFF (ROTATE CLOCKWISE)ALL VALVES ON THE EQUIPMENT BEING USEDBEFORE CONNECTING TO, OR DISCONNECTINGFROM THE REFRIGERANT SYSTEM. FAILURE TOOBSERVE THESE WARNINGS MAY RESULT IN PER-SONAL INJURY.

When servicing the air conditioning system, aR-134a refrigerant recovery/recycling/charging sta-tion that meets SAE Standard J2210 must be used.

Fig. 5 Spring-Lock Coupler - Typical

Contact an automotive service equipment supplier forrefrigerant recovery/recycling/charging equipment.Refer to the operating instructions supplied by theequipment manufacturer for proper care and use ofthis equipment.

A manifold gauge set may be needed with somerecovery/recycling/charging equipment (Fig. 6). Theservice hoses on the gauge set being used shouldhave manual (turn wheel), or automatic back-flowvalves at the service port connector ends. This willprevent refrigerant from being released into theatmosphere.

MANIFOLD GAUGE SET CONNECTIONS

CAUTION: Do not use an R-12 manifold gauge seton an R-134a system. The refrigerants are not com-patible and system damage will result.

LOW PRESSURE GAUGE HOSEThe low pressure hose (Blue with Black stripe)

attaches to the suction service port. This port islocated on the liquid line near the evaporator inlettube at the rear of the engine compartment.

HIGH PRESSURE GAUGE HOSEThe high pressure hose (Red with Black stripe)

attaches to the discharge service port. This port islocated on the manifold directly over the dischargeport of the compressor.

Fig. 6 Manifold Gauge Set - Typical



RECOVERY/RECYCLING/EVACUATION/CHARGINGHOSE

The center manifold hose (Yellow, or White, withBlack stripe) is used to recover, evacuate, and chargethe refrigerant system. When the low or high pres-sure valves on the manifold gauge set are opened,the refrigerant in the system will escape through thishose.

REFRIGERANT SYSTEM SERVICE PORTThe two refrigerant system service ports are used

to charge, recover/recycle, evacuate, and test the airconditioning refrigerant system. Unique service portcoupler sizes are used on the R-134a system, toensure that the refrigerant system is not accidentallycontaminated by the use of the wrong refrigerant(R-12), or refrigerant system service equipment.

The high pressure service port is located on therefrigerant line manifold, near the discharge port ofthe compressor. The low pressure service port islocated on the liquid line at the rear of the enginecompartment, near the evaporator inlet tube.

Each of the service ports has a threaded plasticprotective cap installed over it from the factory. Afterservicing the refrigerant system, always reinstallboth of the service port caps.

VACUUM CHECK VALVEA vacuum check valve is installed in the accessory

vacuum supply line in the engine compartment, nearthe vacuum tap on the engine intake manifold. Thevacuum check valve is designed to allow vacuum toflow in only one direction through the accessory vac-uum supply circuits.

The use of a vacuum check valve helps to maintainthe system vacuum needed to retain the selectedheater-A/C mode settings. The check valve will pre-vent the engine from bleeding down system vacuumthrough the intake manifold during extended heavyengine load (low engine vacuum) operation.

The vacuum check valve cannot be repaired and, iffaulty or damaged, it must be replaced.

VACUUM RESERVOIRThe vacuum reservoir is mounted to the rear of the

right front inner fender wheelhouse in the enginecompartment, under the battery tray. The batteryand battery tray must be removed from the vehicle toaccess the vacuum reservoir for service.

Engine vacuum is stored in the vacuum reservoir.The stored vacuum is used to operate the vacuum-controlled vehicle accessories during periods of lowengine vacuum such as when the vehicle is climbinga steep grade, or under other high engine load oper-ating conditions.

The vacuum reservoir cannot be repaired and, iffaulty or damaged, it must be replaced.

DIAGNOSIS AND TESTING

A/C PERFORMANCEThe air conditioning system is designed to provide

the passenger compartment with low temperatureand low humidity air. The evaporator, located in theheater-A/C housing on the dash panel below theinstrument panel, is cooled to temperatures near thefreezing point. As warm damp air passes through thecooled evaporator, the air transfers its heat to therefrigerant in the evaporator and the moisture in theair condenses on the evaporator fins. During periodsof high heat and humidity, an air conditioning sys-tem will be more effective in the Recirculation Mode.With the system in the Recirculation Mode, only airfrom the passenger compartment passes through theevaporator. As the passenger compartment air dehu-midifies, the air conditioning system performancelevels improve.

Humidity has an important bearing on the temper-ature of the air delivered to the interior of the vehi-cle. It is important to understand the effect thathumidity has on the performance of the air condition-ing system. When humidity is high, the evaporatorhas to perform a double duty. It must lower the airtemperature, and it must lower the temperature ofthe moisture in the air that condenses on the evapo-rator fins. Condensing the moisture in the air trans-fers heat energy into the evaporator fins and tubing.This reduces the amount of heat the evaporator canabsorb from the air. High humidity greatly reducesthe ability of the evaporator to lower the temperatureof the air.

However, evaporator capacity used to reduce theamount of moisture in the air is not wasted. Wring-ing some of the moisture out of the air entering thevehicle adds to the comfort of the passengers.Although, an owner may expect too much from theirair conditioning system on humid days. A perfor-mance test is the best way to determine whether thesystem is performing up to standard. This test alsoprovides valuable clues as to the possible cause oftrouble with the air conditioning system.

Review the Service Warnings and Precautions inthe front of this group before performing this proce-dure. The air temperature in the test room and inthe vehicle must be a minimum of 21° C (70° F) forthis test.

(1) Connect a tachometer and a manifold gaugeset.

(2) Set the heater-A/C mode control switch knob inthe Recirculation Mode position, the temperature

toIfe


DIAGNOSIS AND TESTING (Continued)

control knob in the full cool position, and the blowermotor switch knob in the highest speed position.

(3) Start the engine and hold the idle at 1,000 rpmwith the compressor clutch engaged.

(4) The engine should be at operating temperature.The doors and windows must be open.

(5) Insert a thermometer in the driver side centerA/C (panel) outlet. Operate the engine for five min-utes.

(6) The compressor clutch may cycle, dependingupon the ambient temperature and humidity. If theclutch cycles, unplug the low pressure cycling clutchswitch wire harness connector from the switchlocated on the accumulator (Fig. 7). Place a jumperwire across the terminals of the low pressure cyclingclutch switch wire harness connector.

(7) With the compressor clutch engaged, record thedischarge air temperature and the compressor dis-charge pressure.

(8) Compare the discharge air temperature to thePerformance Temperature and Pressure chart. If thedischarge air temperature is high, see RefrigerantSystem Leaks and Refrigerant System Charge in thisgroup.

(9) Compare the compressor discharge pressurethe Performance Temperature and Pressure chart.the compressor discharge pressure is high, see thPressure Diagnosis chart.

Fig. 7 Low Pressure Cycling Clutch Switch - Typical

Performance Temperature and Pressure

Ambient AirTemperature

21° C(70° F)

27° C(80° F)

32° C(90° F)

38° C(100° F)

43° C(110° F)

Air Temperatureat Center PanelOutlet

-3 to 3° C(27 to 38° F)

1 to 7° C(33 to 44° F)

3 to 9° C(37 to 48° F)

6 to 13° C(43 to 55° F)

10 to 18° C(50 to 64° F)

Evaporator InletPressure atCharge Port

179 to 241 kPa(26 to 35 psi)

221 to 283 kPa(32 to 41 psi)

262 to 324 kPa(38 to 47 psi)

303 to 365 kPa(44 to 53 psi)

345 to 414 kPa(50 to 60 psi)

CompressorDischargePressure

1240 to 1655 kPa(180 to 240 psi)

1380 to 1790 kPa(200 to 260 psi)

1720 to 2070 kPa(250 to 300 psi)

1860 to 2345 kPa(270 to 340 psi)

2070 to 2690 kPa(300 to 390 psi)



Pressure Diagnosis

Condition Possible Causes Correction

Rapid compressorclutch cycling (ten ormore cycles perminute).

1. Low refrigerant system charge. 1. See Refrigerant System Leaks in thisgroup. Test the refrigerant system forleaks. Repair, evacuate and charge therefrigerant system, if required.

Equal pressures, but thecompressor clutch doesnot engage.

1. No refrigerant in the refrigerant system.2. Faulty fuse.3. Faulty compressor clutch coil.4. Faulty compressor clutch relay.5. Improperly installed or faulty lowpressure cycling clutch switch.6. Faulty high pressure cut-off switch.7. Faulty Powertrain Control Module(PCM).

1. See Refrigerant System Leaks in thisgroup. Test the refrigerant system forleaks. Repair, evacuate and charge therefrigerant system, if required.2. Check the fuses in the PowerDistribution Center and the fuseblockmodule. Repair the shorted circuit orcomponent and replace the fuses, ifrequired.3. See Compressor Clutch Coil in thisgroup. Test the compressor clutch coil andreplace, if required.4. See Compressor Clutch Relay in thisgroup. Test the compressor clutch relayand relay circuits. Repair the circuits orreplace the relay, if required.5. See Low Pressure Cycling ClutchSwitch in this group. Test the low pressurecycling clutch switch and tighten orreplace, if required.6. See High Pressure Cut-Off Switch inthis group. Test the high pressure cut-offswitch and replace, if required.7. Refer to the proper DiagnosticProcedures manual for testing of thePCM. Test the PCM and replace, ifrequired.

Normal pressures, butA/C Performance Testair temperatures atcenter panel outlet aretoo high.

1. Excessive refrigerant oil in system.2. Temperature control cable improperlyinstalled or faulty.3. Blend-air door inoperative or sealingimproperly.

1. See Refrigerant Oil Level in this group.Recover the refrigerant from therefrigerant system and inspect therefrigerant oil content. Restore therefrigerant oil to the proper level, ifrequired.2. See Temperature Control Cable in thisgroup. Inspect the temperature controlcable for proper routing and operation andcorrect, if required.3. See Blend-Air Door under Heater-A/CHousing Door in this group. Inspect theblend-air door for proper operation andsealing and correct, if required.



Pressure Diagnosis

Condition Possible Causes Correction

The low side pressure isnormal or slightly low,and the high sidepressure is too low.

1. Low refrigerant system charge.2. Refrigerant flow through theaccumulator is restricted.3. Refrigerant flow through the evaporatorcoil is restricted.4. Faulty compressor.

1. See Refrigerant System Leaks in thisgroup. Test the refrigerant system forleaks. Repair, evacuate and charge therefrigerant system, if required.2. See Accumulator in this group. Replacethe restricted accumulator, if required.3. See Evaporator Coil in this group.Replace the restricted evaporator coil, ifrequired.4. See Compressor in this group. Replacethe compressor, if required.

The low side pressure isnormal or slightly high,and the high sidepressure is too high.

1. Condenser air flow restricted.2. Inoperative cooling fan.3. Refrigerant system overcharged.4. Air in the refrigerant system.5. Engine overheating.

1. Check the condenser for damaged fins,foreign objects obstructing air flow throughthe condenser fins, and missing orimproperly installed air seals. Refer toGroup 7 - Cooling System for moreinformation on air seals. Clean, repair, orreplace components as required.2. Refer to Group 7 - Cooling System formore information. Test the cooling fan andreplace, if required.3. See Refrigerant System Charge in thisgroup. Recover the refrigerant from therefrigerant system. Charge the refrigerantsystem to the proper level, if required.4. See Refrigerant System Leaks in thisgroup. Test the refrigerant system forleaks. Repair, evacuate and charge therefrigerant system, if required.5. Refer to Group 7 - Cooling System formore information. Test the cooling systemand repair, if required.

The low side pressure istoo high, and the highside pressure is too low.

1. Accessory drive belt slipping.2. Fixed orifice tube not installed.3. Faulty compressor.

1. Refer to Group 7 - Cooling System formore information. Inspect the accessorydrive belt condition and tension. Tightenor replace the accessory drive belt, ifrequired.2. See Fixed Orifice Tube in this group.Install the missing fixed orifice tube, ifrequired.3. See Compressor in this group. Replacethe compressor, if required.

The low side pressure istoo low, and the highside pressure is toohigh.

1. Restricted refrigerant flow through therefrigerant lines.2. Restricted refrigerant flow through thefixed orifice tube.3. Restricted refrigerant flow through thecondenser.

1. See Liquid Line and Suction andDischarge Line in this group. Inspect therefrigerant lines for kinks, tight bends orimproper routing. Correct the routing orreplace the refrigerant line, if required.2. See Fixed Orifice Tube in this group.Replace the restricted fixed orifice tube, ifrequired.3. See Condenser in this group. Replacethe restricted condenser, if required.



HEATER PERFORMANCEBefore performing the following tests, refer to

Group 7 - Cooling System for the procedures to checkthe radiator coolant level, serpentine drive belt ten-sion, radiator air flow and the radiator fan operation.Also be certain that the accessory vacuum supplyline is connected at the engine intake manifold.

MAXIMUM HEATER OUTPUTEngine coolant is delivered to the heater core

through two heater hoses. With the engine idling atnormal operating temperature, set the temperaturecontrol knob in the full hot position, the mode controlswitch knob in the floor heat position, and the blowermotor switch knob in the highest speed position.Using a test thermometer, check the temperature ofthe air being discharged at the heater-A/C housingfloor outlets. Compare the test thermometer readingto the Temperature Reference chart.

If the floor outlet air temperature is too low, referto Group 7 - Cooling System to check the engine cool-ant temperature specifications. Both of the heaterhoses should be hot to the touch. The coolant returnheater hose should be slightly cooler than the coolantsupply heater hose. If the return hose is much coolerthan the supply hose, locate and repair the enginecoolant flow obstruction in the cooling system. Referto Group 7 - Cooling System for the procedures.

OBSTRUCTED COOLANT FLOWPossible locations or causes of obstructed coolant flow:• Pinched or kinked heater hoses.• Improper heater hose routing.• Plugged heater hoses or supply and return ports

at the cooling system connections.• A plugged heater core.If proper coolant flow through the cooling system is

verified, and heater outlet air temperature is stilllow, a mechanical problem may exist.

MECHANICAL PROBLEMSPossible locations or causes of insufficient heat:• An obstructed cowl air intake.• Obstructed heater system outlets.• A blend-air door not functioning properly.

TEMPERATURE CONTROLIf the heater outlet air temperature cannot be

adjusted with the temperature control knob on the heat-er-A/C control panel, the following could require service:

• The heater-A/C control.• The temperature control cable.• The blend-air door.• Improper engine coolant temperature.

VACUUM SYSTEMVacuum control is used to operate the mode doors

in the heater-A/C housing. Testing of the heater-A/Cmode control switch operation will determine if thevacuum, and mechanical controls are functioning.However, it is possible that a vacuum control systemthat operates perfectly at engine idle (high enginevacuum) may not function properly at high enginespeeds or loads (low engine vacuum). This can becaused by leaks in the vacuum system, or a faultyvacuum check valve.

A vacuum system test will help to identify thesource of poor vacuum system performance or vac-uum system leaks. Before starting this test, stop theengine and make certain that the problem isn’t a dis-connected vacuum supply tube at the engine intakemanifold vacuum tap or the vacuum reservoir.

Use an adjustable vacuum test set (Special ToolC-3707) and a suitable vacuum pump to test theheater-A/C vacuum control system. With a fingerplaced over the end of the vacuum test hose probe(Fig. 8), adjust the bleed valve on the test set gaugeto obtain a vacuum of exactly 27 kPa (8 in. Hg.).Release and block the end of the probe several timesto verify that the vacuum reading returns to theexact 27 kPa (8 in. Hg.) setting. Otherwise, a falsereading will be obtained during testing.

Fig. 8 Adjust Vacuum Test Bleed Valve

Temperature Reference

Ambient Air Temperature 15.5° C(60° F)

21.1° C(70° F)

26.6° C(80° F)

32.2° C(90° F)

Minimum Air Temperature at FloorOutlet

62.2° C(144° F)

63.8° C(147° F)

65.5° C(150° F)

67.2° C(153° F)



VACUUM CHECK VALVE(1) Remove the vacuum check valve. The valve is

located in the (black) vacuum supply tube at theintake manifold vacuum tap.

(2) Connect the test set vacuum supply hose to theheater (natural color) side of the valve. When con-nected to this side of the check valve, no vacuumshould pass and the test set gauge should return tothe 27 kPa (8 in. Hg.) setting. If OK, go to Step 3. Ifnot OK, replace the faulty valve.

(3) Connect the test set vacuum supply hose to theengine vacuum (black color) side of the valve. Whenconnected to this side of the check valve, vacuumshould flow through the valve without restriction. Ifnot OK, replace the faulty valve.

HEATER-A/C CONTROLS(1) Connect the test set vacuum probe to the heat-

er-A/C vacuum supply (black) tube in the enginecompartment. Position the test set gauge so that itcan be viewed from the passenger compartment.

(2) Place the heater-A/C mode control switch knob ineach mode position, one position at a time, and pauseafter each selection. The test set gauge should return tothe 27 kPa (8 in. Hg.) setting shortly after each selec-tion is made. If not OK, a component or vacuum line inthe vacuum circuit of the selected mode has a leak. Seethe procedure in Locating Vacuum Leaks.

CAUTION: Do not use lubricant on the switch portsor in the holes in the plug, as lubricant will ruin thevacuum valve in the switch. A drop of clean waterin the connector plug holes will help the connectorslide onto the switch ports.

LOCATING VACUUM LEAKS

WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS,REFER TO GROUP 8M - PASSIVE RESTRAINT SYS-

TEMS BEFORE ATTEMPTING ANY STEERING WHEEL,STEERING COLUMN, OR INSTRUMENT PANEL COM-PONENT DIAGNOSIS OR SERVICE. FAILURE TO TAKETHE PROPER PRECAUTIONS COULD RESULT INACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLEPERSONAL INJURY.

(1) Disconnect the vacuum harness connector nearthe back of the heater-A/C mode control switch onthe control panel.

(2) Connect the test set vacuum hose probe to eachport in the vacuum harness connector, one at a time,and pause after each connection (Fig. 9). The test setgauge should return to the 27 kPa (8 in. Hg.) settingshortly after each connection is made. If OK, replace thefaulty mode control switch. If not OK, go to Step 3.

(3) Determine the vacuum line color of the vacuumcircuit that is leaking. To determine the vacuum linecolors, refer to the Vacuum Circuits chart (Fig. 10) or(Fig. 11).

Fig. 9 Vacuum Circuit Test



Fig. 10 Vacuum Circuits - Heater Only



Fig. 11 Vacuum Circuits - Heater-A/C



(4) Disconnect and plug the vacuum line from thecomponent (fitting, actuator, valve, switch, or reser-voir) on the other end of the leaking circuit. Instru-ment panel disassembly or removal may be necessaryto gain access to some components.

(5) Connect the test set hose or probe to the openend of the leaking circuit. The test set gauge shouldreturn to the 27 kPa (8 in. Hg.) setting shortly aftereach connection is made. If OK, replace the faultydisconnected component. If not OK, go to Step 6.

(6) To locate a leak in a vacuum line, leave oneend of the line plugged and connect the test set hoseor probe to the other end. Run your fingers slowlyalong the line while watching the test set gauge. Thevacuum reading will fluctuate when your fingers con-tact the source of the leak. To repair the vacuumline, cut out the leaking section of the line. Then,insert the loose ends of the line into a suitable lengthof 3 millimeter (1/8-inch) inside diameter rubberhose.

BLOWER MOTOR

WARNING: ON VEHICLES EQUIPPED WITH AIR-BAGS, REFER TO GROUP 8M - PASSIVERESTRAINT SYSTEMS BEFORE ATTEMPTING ANYSTEERING WHEEL, STEERING COLUMN, ORINSTRUMENT PANEL COMPONENT DIAGNOSIS ORSERVICE. FAILURE TO TAKE THE PROPER PRE-CAUTIONS COULD RESULT IN ACCIDENTAL AIR-BAG DEPLOYMENT AND POSSIBLE PERSONALINJURY.

For circuit descriptions and diagrams, refer to8W-42 - Air Conditioning/Heater in Group 8W - Wir-ing Diagrams. Possible causes of an inoperativeblower motor include:

• Faulty fuse• Faulty blower motor circuit wiring or wire har-

ness connections• Faulty blower motor resistor• Faulty blower motor relay• Faulty blower motor switch• Faulty heater-A/C mode control switch• Faulty blower motor.Possible causes of the blower motor not operating

in all speeds include:• Faulty fuse• Faulty blower motor switch• Faulty blower motor resistor• Faulty blower motor relay• Faulty blower motor circuit wiring or wire har-

ness connectors.

VIBRATIONPossible causes of blower motor vibration include:• Improper blower motor mounting

• Improper blower wheel mounting• Blower wheel out of balance or bent• Blower motor faulty.

NOISETo verify that the blower is the source of the noise,

unplug the blower motor wire harness connector andoperate the heater-A/C system. If the noise goesaway, possible causes include:

• Foreign material in the heater-A/C housing• Improper blower motor mounting• Improper blower wheel mounting• Blower motor faulty.

BLOWER MOTOR RELAY


RELAY TESTThe blower motor relay (Fig. 12) is located in a

wire harness connector that is secured to the heater-A/C housing behind the glove box on the passengerside of the vehicle, next to the heater-A/C wire har-ness connector in the passenger compartment.Remove the relay from its connector to perform thefollowing tests:

(1) A relay in the de-energized position shouldhave continuity between terminals 87A and 30, andno continuity between terminals 87 and 30. If OK, goto Step 2. If not OK, replace the faulty relay.

(2) Resistance between terminals 85 and 86 (elec-tromagnet) should be 75 6 5 ohms. If OK, go to Step3. If not OK, replace the faulty relay.

(3) Connect a battery to terminals 85 and 86.There should now be continuity between terminals30 and 87, and no continuity between terminals 87Aand 30. If OK, see the Relay Circuit Test procedurein this group. If not OK, replace the faulty relay.

RELAY CIRCUIT TEST(1) The relay common feed terminal cavity (30) is

connected to the blower motor. This terminal suppliesfused battery feed directly from a fuse in the PowerDistribution Center (PDC) when the relay is ener-gized, and ignition switched battery feed from a fusein the fuseblock module through the blower motorresistor when the relay is de-energized. There shouldbe continuity between this cavity and the blower



motor feed circuit cavity of the blower motor wireharness connector at all times. If OK, go to Step 2. Ifnot OK, repair the open circuit as required.

(2) The relay normally closed terminal cavity (87A)is connected to the blower motor resistor output.When the relay is de-energized, terminal 87A is con-nected to terminal 30 and provides the blower motorresistor output to the blower motor feed circuit.There should be continuity between this cavity andthe blower resistor outputs circuit cavity of theblower motor resistor wire harness connector at alltimes. If OK, go to Step 3. If not OK, repair the opencircuit as required.

(3) The relay normally open terminal cavity (87) isconnected to a fused battery feed from the PDC.When the relay is energized, terminal 87 is con-nected to terminal 30 and provides full battery cur-rent to the blower motor feed circuit. There should bebattery voltage at this cavity at all times. If OK, goto Step 4. If not OK, repair the open circuit to thePDC as required.

(4) The coil battery terminal cavity (86) is con-nected to the high speed output contacts of theblower motor switch. When the blower motor switchis placed in the high speed position, fused ignitionswitch output is directed to the relay electromagneticcoil to energize the relay. There should be continuitybetween the cavity for relay terminal 86 and the highblower motor relay control circuit cavity of the blowermotor switch wire harness connector at all times. IfOK, go to Step 5. If not OK, repair the open circuitas required.

(5) The coil ground terminal cavity (85) is con-nected to ground. This terminal supplies the groundfor the relay electromagnet coil. There should be con-tinuity between the cavity for relay terminal 85 anda good ground at all times. If not OK, repair the opencircuit as required.

Fig. 12 Blower Motor Relay

BLOWER MOTOR RESISTORFor circuit descriptions and diagrams, refer to

8W-42 - Air Conditioning/Heater in Group 8W - Wir-ing Diagrams.


(1) Disconnect and isolate the battery negativecable.

(2) Remove the kick cover from the heater-A/Chousing and unplug the wire harness connector fromthe blower motor resistor.

(3) Check for continuity between each of theblower motor switch input terminals of the resistorand the resistor output terminal. In each case thereshould be continuity. If OK, repair the wire harnesscircuits between the blower motor switch and theblower motor resistor or blower motor relay asrequired. If not OK, replace the faulty blower motorresistor.

BLOWER MOTOR SWITCHFor circuit descriptions and diagrams, refer to



(1) Turn the ignition switch to the On position andcheck for battery voltage at the fuse in the fuseblockmodule. If OK, go to Step 2. If not OK, repair theshorted circuit or component as required and replacethe faulty fuse.

(2) Turn the ignition switch to the Off position.Disconnect and isolate the battery negative cable.Remove the heater-A/C control from the instrumentpanel, but do not unplug the wire harness connec-tors. Connect the battery negative cable. Turn theignition switch to the On position. Check for batteryvoltage at the fused ignition switch output (run) cir-cuit cavity of the heater-A/C mode control switch



wire harness connector. If OK, go to Step 3. If notOK, repair the open circuit to the fuseblock moduleas required.

(3) Select any one of the heater-A/C mode controlpositions except Off to turn the system on. Check forbattery voltage at the low blower motor driver circuitcavity of the heater-A/C mode control switch wireharness connector. If OK, go to Step 4. If not OK,replace the faulty heater-A/C mode control switch.

(4) Check for battery voltage at the low blowermotor driver circuit cavity of the blower motor switchwire harness connector. If OK, go to Step 5. If notOK, repair the open circuit to the heater-A/C modecontrol switch wire harness connector as required.

(5) Check for battery voltage at each of theremaining blower motor switch wire harness connec-tor cavities as you move the switch to each blowermotor speed position. Voltage should be present ineach cavity at only one switch position. If OK, seethe diagnosis for the blower motor resistor and/or theblower motor relay in this group. If not OK, replacethe faulty blower motor switch.

COMPRESSORWhen investigating an air conditioning related

noise, you must first know the conditions underwhich the noise occurs. These conditions include:weather, vehicle speed, transmission in gear or neu-tral, engine temperature, and any other special con-ditions.

Noises that develop during air conditioning opera-tion can often be misleading. For example: Whatsounds like a failed front bearing or connecting rod,may be caused by loose bolts, nuts, mounting brack-ets, or a loose clutch assembly. Verify serpentinedrive belt tension. Improper belt tension can cause amisleading noise when the compressor is engaged.The noise may not occur when the compressor is dis-engaged.

Drive belts are speed sensitive. At different enginespeeds and depending upon belt tension, belts candevelop noises that are mistaken for a compressornoise.

(1) Select a quiet area for testing. Duplicate thecomplaint conditions as much as possible. Switch thecompressor on and off several times to clearly iden-tify the compressor noise. Listen to the compressorclutch while engaged and disengaged.

(2) To duplicate a high-ambient temperature condi-tion (high head pressure), restrict the air flowthrough the condenser. Install a manifold gauge setto make sure that the discharge pressure does notexceed 2070 kPa (300 psi).

(3) Tighten all compressor mounting bolts, theclutch mounting nut, the clutch coil mounting screw

or nut, and the serpentine drive belt to the correctspecifications.

(4) Check the refrigerant system plumbing for rub-bing or interference, which can cause unusual noises.

(5) Check the refrigerant system charge. SeeRefrigerant System Charge in this group for the pro-cedures.

(6) Check the compressor noise as in Step 1.(7) If the noise still exists, loosen the compressor

mounting bolts and tighten again. Repeat Step 1.(8) If the noise continues, replace the compressor

and repeat Step 1.

COMPRESSOR CLUTCH COILFor circuit descriptions and diagrams, refer to

8W-42 - Air Conditioning/Heater in Group 8W - Wir-ing Diagrams. The battery must be fully-chargedbefore performing the following tests. Refer to Group8A - Battery for more information.

(1) Connect an ammeter (0 to 10 ampere scale) inseries with the clutch coil terminal. Use a voltmeter(0 to 20 volt scale) with clip-type leads for measuringthe voltage across the battery and the compressorclutch coil.

(2) With the heater-A/C mode control switch in anyA/C mode, and the blower motor switch in the lowestspeed position, start the engine and run it at normalidle.

(3) The compressor clutch coil voltage should readwithin two volts of the battery voltage. If there isvoltage at the clutch coil, but the reading is notwithin two volts of the battery voltage, test theclutch coil feed circuit for excessive voltage drop andrepair as required. If there is no voltage reading atthe clutch coil, use a DRB scan tool and the properDiagnostic Procedures manual for testing of the com-pressor clutch circuit. The following componentsmust be checked and repaired as required before youcan complete testing of the clutch coil:

• Fuses in the fuseblock module and the PowerDistribution Center (PDC)

• Heater-A/C mode control switch• Compressor clutch relay• High pressure cut-off switch• Low pressure cycling clutch switch• Powertrain Control Module (PCM).(4) The compressor clutch coil is acceptable if the

current draw measured at the clutch coil is 2.0 to 3.9amperes with the electrical system voltage at 11.5 to12.5 volts. This should only be checked with the workarea temperature at 21° C (70° F). If system voltageis more than 12.5 volts, add electrical loads by turn-ing on electrical accessories until the system voltagedrops below 12.5 volts.



(a) If the clutch coil current reading is fouramperes or more, the coil is shorted and should bereplaced.

(b) If the clutch coil current reading is zero, thecoil is open and should be replaced.

COMPRESSOR CLUTCH RELAYFor circuit descriptions and diagrams, refer to


RELAY TESTThe compressor clutch relay (Fig. 13) is located in

the Power Distribution Center (PDC). Refer to thePDC label for relay identification and location.Remove the relay from the PDC to perform the fol-lowing tests:

(1) A relay in the de-energized position shouldhave continuity between terminals 87A and 30, andno continuity between terminals 87 and 30. If OK, goto Step 2. If not OK, replace the faulty relay.

(2) Resistance between terminals 85 and 86 (elec-tromagnet) should be 75 6 5 ohms. If OK, go to Step3. If not OK, replace the faulty relay.

(3) Connect a battery to terminals 85 and 86.There should now be continuity between terminals30 and 87, and no continuity between terminals 87Aand 30. If OK, see the Relay Circuit Test procedurein this group. If not OK, replace the faulty relay.

RELAY CIRCUIT TESTFor circuit descriptions and diagrams, refer to


(1) The relay common feed terminal cavity (30) isconnected to fused battery feed. There should be bat-tery voltage at the cavity for relay terminal 30 at alltimes. If OK, go to Step 2. If not OK, repair the opencircuit to the fuse in the PDC as required.

Fig. 13 Compressor Clutch Relay

(2) The relay normally closed terminal (87A) is notused in this application. Go to Step 3.

(3) The relay normally open terminal cavity (87) isconnected to the compressor clutch coil. There shouldbe continuity between this cavity and the A/C com-pressor clutch relay output circuit cavity of the com-pressor clutch coil wire harness connector. If OK, goto Step 4. If not OK, repair the open circuit asrequired.

(4) The relay coil battery terminal (86) is con-nected to the fused ignition switch output (run/start)circuit. There should be battery voltage at the cavityfor relay terminal 86 with the ignition switch in theOn position. If OK, go to Step 5. If not OK, repair theopen circuit to the fuse in the fuseblock module asrequired.

(5) The coil ground terminal cavity (85) is switchedto ground through the Powertrain Control Module(PCM). There should be continuity between this cav-ity and the A/C compressor clutch relay control cir-cuit cavity of the PCM wire harness connector C(gray) at all times. If not OK, repair the open circuitas required.

HIGH PRESSURE CUT-OFF SWITCHBefore performing diagnosis of the high pressure

cut-off switch, verify that the refrigerant system hasthe correct refrigerant charge. See Refrigerant Sys-tem Charge in this group for the procedures.

For circuit descriptions and diagrams, refer to8W-42 - Air Conditioning/Heater in Group 8W - Wir-ing Diagrams.


(2) Unplug the high pressure cut-off switch wireharness connector from the switch.

(3) Check for continuity between the two terminalsof the high pressure cut-off switch. There should becontinuity. If OK, test and repair the A/C switchsense circuit as required. If not OK, replace thefaulty switch.

LOW PRESSURE CYCLING CLUTCH SWITCHBefore performing diagnosis of the low pressure

cycling clutch switch, be certain that the switch isproperly installed on the accumulator fitting. If theswitch is too loose it may not open the Schrader-typevalve in the accumulator fitting, which will preventthe switch from correctly monitoring the refrigerantsystem pressure.

Also verify that the refrigerant system has the cor-rect refrigerant charge. See Refrigerant SystemCharge in this group for the procedures.

For circuit descriptions and diagrams, refer to8W-42 - Air Conditioning/Heater in Group 8W - Wir-ing Diagrams.




(2) Unplug the low pressure cycling clutch switchwire harness connector from the switch on the accu-mulator fitting.

(3) Install a jumper wire between the two cavitiesof the low pressure cycling clutch switch wire har-ness connector.

(4) Connect a manifold gauge set to the refrigerantsystem service ports. See Refrigerant System ServiceEquipment in this group for the procedures.

(5) Connect the battery negative cable.(6) Place the heater-A/C mode control switch knob

in any A/C position and start the engine.(7) Check for continuity between the two terminals

of the low pressure cycling clutch switch. Thereshould be continuity with a suction pressure readingof 262 kPa (38 psi) or above, and no continuity with asuction pressure reading of 141 kPa (20.5 psi) orbelow. If OK, test and repair the A/C switch sensecircuit as required. If not OK, replace the faultyswitch.

REFRIGERANT SYSTEM LEAKS

WARNING: REVIEW THE WARNINGS AND CAU-TIONS IN THE FRONT OF THIS GROUP BEFORELEAK TESTING THE SYSTEM.

If the air conditioning system is not cooling prop-erly, determine if the refrigerant system is fully-charged. See A/C Performance in this group for theprocedures. If the refrigerant system is low or empty;a leak at a refrigerant line, connector fitting, compo-nent, or component seal is likely.

An electronic leak detector designed for R-134arefrigerant is recommended for locating and confirm-ing refrigerant system leaks. Refer to the operatinginstructions supplied by the equipment manufacturerfor proper care and use of this equipment.

An oily residue on or near refrigerant system lines,connector fittings, components, or component sealscan indicate the general location of a possible refrig-erant leak. However, the exact leak location shouldbe confirmed with an electronic leak detector prior tocomponent repair or replacement.

To detect a leak in the refrigerant system, performone of the following procedures:

SYSTEM EMPTY(1) Evacuate the refrigerant system. See Refriger-

ant System Evacuate in this group for the proce-dures.

(2) Connect and dispense 0.283 kilograms (0.625pounds or 10 ounces) of R-134a refrigerant into theevacuated refrigerant system. See Refrigerant Sys-tem Charge in this group for the procedures.

(3) Position the vehicle in a wind-free work area.This will aid in detecting small leaks.

(4) With the engine not running, use a electronicR-134a leak detector and search for leaks. BecauseR-134a refrigerant is heavier than air, the leak detec-tor probe should be moved slowly along the bottomside of all refrigerant lines, connector fittings andcomponents.

(5) To inspect the evaporator coil for leaks, insertthe electronic leak detector probe into the centerinstrument panel outlet. Set the blower motor switchto the lowest speed position, and the mode controlswitch in the Recirculation Mode.

SYSTEM LOW(1) Position the vehicle in a wind-free work area.

This will aid in detecting small leaks.(2) Bring the refrigerant system up to operating

temperature and pressure. This is done by allowingthe engine to run with the air conditioning systemturned on for five minutes.

(3) With the engine not running, use a electronicR-134a leak detector and search for leaks. BecauseR-134a refrigerant is heavier than air, the leak detec-tor probe should be moved slowly along the bottomside of all refrigerant lines, connector fittings andcomponents.

(4) To inspect the evaporator coil for leaks, insertthe electronic leak detector probe into the centerinstrument panel outlet. Set the blower motor switchto the lowest speed position, and the mode controlswitch in the Recirculation Mode.

SERVICE PROCEDURES

REFRIGERANT RECOVERY

WARNING: REVIEW THE WARNINGS AND CAU-TIONS IN THE FRONT OF THIS GROUP BEFORERECOVERING REFRIGERANT.

A R-134a refrigerant recovery/recycling/chargingstation that meets SAE Standard J2210 must beused to recover the refrigerant from an R-134a refrig-erant system. Refer to the operating instructions sup-plied by the equipment manufacturer for proper careand use of this equipment.

REFRIGERANT SYSTEM EVACUATE

WARNING: REVIEW THE WARNINGS AND CAU-TIONS IN THE FRONT OF THIS GROUP BEFOREEVACUATING THE SYSTEM.

If the refrigerant system has been open to theatmosphere, it must be evacuated before the systemcan be charged. If moisture and air enters the system


SERVICE PROCEDURES (Continued)

and becomes mixed with the refrigerant, the com-pressor head pressure will rise above acceptableoperating levels. This will reduce the performance ofthe air conditioner and damage the compressor.Evacuating the refrigerant system will remove theair and boil the moisture out of the system at nearroom temperature. To evacuate the refrigerant sys-tem, use the following procedure:

(1) Connect a R-134a refrigerant recovery/recy-cling/charging station that meets SAE StandardJ2210 and a manifold gauge set to the refrigerantsystem of the vehicle.

(2) Open the low and high side valves and startthe charging station vacuum pump. When the suc-tion gauge reads 88 kPa (26 in. Hg.) vacuum orgreater, close all of the valves and turn off the vac-uum pump.

(a) If the refrigerant system fails to reach thespecified vacuum, the system has a leak that mustbe corrected. See Refrigerant System Leaks in thisgroup.

(b) If the refrigerant system maintains the spec-ified vacuum for five minutes, restart the vacuumpump, open the suction and discharge valves andevacuate the system for an additional ten minutes.(3) Close all of the valves, and turn off the charg-

ing station vacuum pump.(4) The refrigerant system is now ready to be

charged with R-134a refrigerant. See RefrigerantSystem Charge in this group.

REFRIGERANT SYSTEM CHARGE

WARNING: REVIEW THE WARNINGS AND CAU-TIONS IN THE FRONT OF THIS GROUP BEFORECHARGING THE REFRIGERANT SYSTEM.

After the refrigerant system has been tested forleaks and evacuated, a refrigerant charge can beinjected into the system. See Refrigerant ChargeCapacity for the proper amount of the refrigerantcharge.

A R-134a refrigerant recovery/recycling/chargingstation that meets SAE Standard J2210 must beused to charge the refrigerant system with R-134arefrigerant. Refer to the operating instructions sup-plied by the equipment manufacturer for proper careand use of this equipment.

REFRIGERANT CHARGE CAPACITYThe R-134a refrigerant system charge capacity for

this vehicle is 0.567 kilograms (1.25 pounds).

REFRIGERANT OIL LEVELWhen an air conditioning system is assembled at

the factory, all components except the compressor arerefrigerant oil free. After the refrigerant system hasbeen charged and operated, the refrigerant oil in thecompressor is dispersed throughout the refrigerantsystem. The accumulator, evaporator, condenser, andcompressor will each retain a significant amount ofthe needed refrigerant oil.

It is important to have the correct amount of oil inthe refrigerant system. This ensures proper lubrica-tion of the compressor. Too little oil will result indamage to the compressor. Too much oil will reducethe cooling capacity of the air conditioning system.

It will not be necessary to check the oil level in thecompressor or to add oil, unless there has been an oilloss. An oil loss may occur due to a rupture or leakfrom a refrigerant line, a connector fitting, a compo-nent, or a component seal. If a leak occurs, add 30milliliters (1 fluid ounce) of refrigerant oil to therefrigerant system after the repair has been made.Refrigerant oil loss will be evident at the leak pointby the presence of a wet, shiny surface around theleak.

Refrigerant oil must be added when a accumulator,evaporator coil, or condenser are replaced. Refer tothe Refrigerant Oil Capacities chart. When a com-pressor is replaced, the refrigerant oil must bedrained from the old compressor and measured.Drain all of the refrigerant oil from the new compres-sor, then fill the new compressor with the sameamount of refrigerant oil that was drained out of theold compressor.

REMOVAL AND INSTALLATION

REFRIGERANT LINE COUPLER

WARNING: REVIEW THE WARNINGS AND CAU-TIONS IN THE FRONT OF THIS GROUP BEFOREPERFORMING THE FOLLOWING OPERATION.

Refrigerant Oil Capacities

Component ml oz

A/C System 240 8.1

Accumulator 120 4

Condenser 30 1

Evaporator 60 2

Compressor drain and measure the oil from theold compressor - see text.


REMOVAL AND INSTALLATION (Continued)

REMOVAL(1) Recover the refrigerant from the refrigerant

system. See Refrigerant Recovery in this group forthe procedures.

(2) Remove the secondary clip from the spring-lockcoupler.

(3) Fit the proper size A/C line disconnect tool(Special Tool Kit 7193) over the spring-lock couplercage (Fig. 14).

(4) Close the two halves of the A/C line disconnecttool around the spring-lock coupler.

(5) Push the A/C line disconnect tool into the openside of the coupler cage to expand the garter spring.Once the garter spring is expanded and while stillpushing the disconnect tool into the open side of thecoupler cage, pull on the refrigerant line attached tothe female half of the coupler fitting until the flangeon the female fitting is separated from the garterspring and cage on the male fitting within the dis-connect tool.

NOTE: The garter spring may not release if the A/Cline disconnect tool is cocked while pushing it intothe coupler cage opening.

(6) Open and remove the A/C line disconnect toolfrom the disconnected spring-lock coupler.

(7) Complete the separation of the two halves ofthe coupler fitting.

Fig. 14 Refrigerant Line Spring-Lock CouplerDisconnect

INSTALLATION(1) Check to ensure that the garter spring is

located within the cage of the male coupler fitting,and that the garter spring is not damaged.

(a) If the garter spring is missing, install a newspring by pushing it into the coupler cage opening.

(b) If the garter spring is damaged, remove itfrom the coupler cage with a small wire hook (DONOT use a screwdriver) and install a new garterspring.(2) Clean any dirt or foreign material from both

halves of the coupler fitting.(3) Install new O-rings on the male half of the cou-

pler fitting.

CAUTION: Use only the specified O-rings as theyare made of a special material for the R-134a sys-tem. The use of any other O-rings may allow theconnection to leak intermittently during vehicleoperation.

(4) Lubricate the male fitting and O-rings, and theinside of the female fitting with clean R-134a refrig-erant oil. Use only refrigerant oil of the type recom-mended for the compressor in the vehicle.

(5) Fit the female half of the coupler fitting overthe male half of the fitting.

(6) Push together firmly on the two halves of thecoupler fitting until the garter spring in the cage onthe male half of the fitting snaps over the flangedend on the female half of the fitting.

(7) Ensure that the spring-lock coupler is fullyengaged by trying to separate the two coupler halves.This is done by pulling the refrigerant lines on eitherside of the coupler away from each other.

(8) Reinstall the secondary clip over the spring-lock coupler cage.

HIGH PRESSURE CUT-OFF SWITCH

REMOVAL(1) Disconnect and isolate the battery negative

cable.(2) Unplug the wire harness connector from the

high pressure cut-off switch, which is mounted to afitting on the discharge line between the compressorand the condenser inlet (Fig. 15).

(3) Unscrew the high pressure cut-off switch fromthe discharge line fitting.

(4) Remove the high pressure cut-off switch fromthe vehicle.

(5) Remove the O-ring seal from the discharge linefitting and discard.

INSTALLATION(1) Lubricate a new O-ring seal with clean refrig-

erant oil and install it on the discharge line fitting.



Use only the specified O-rings as they are made of aspecial material for the R-134a system. Use onlyrefrigerant oil of the type recommended for the com-pressor in the vehicle.

(2) Install and tighten the high pressure cut-offswitch on the discharge line fitting.

(3) Plug the wire harness connector into the highpressure cut-off switch.

(4) Connect the battery negative cable.

SUCTION AND DISCHARGE LINEAny kinks or sharp bends in the refrigerant plumb-

ing will reduce the capacity of the entire air condi-tioning system. Kinks and sharp bends reduce theflow of refrigerant in the system. A good rule for theflexible hose refrigerant lines is to keep the radius ofall bends at least ten times the diameter of the hose.In addition, the flexible hose refrigerant lines shouldbe routed so they are at least 80 millimeters (3inches) from the exhaust manifold.

High pressures are produced in the refrigerant sys-tem when the air conditioning compressor is operat-ing. Extreme care must be exercised to make surethat each of the refrigerant system connections ispressure-tight and leak free. It is a good practice toinspect all flexible hose refrigerant lines at least oncea year to make sure they are in good condition andproperly routed.


Fig. 15 High Pressure Cut-Off Switch Remove/Install- Typical


cable.(2) Recover the refrigerant from the refrigerant


(3) Unplug the wire harness connector from thehigh pressure cut-off switch.

(4) Remove the bolt that secures the discharge linesupport bracket to the compressor (Fig. 16).

(5) Disconnect the discharge line refrigerant linecoupler from the condenser inlet tube. See Refriger-ant Line Coupler in this group for the procedures.Install plugs in, or tape over all of the opened refrig-erant line fittings.

(6) Disconnect the suction line from the accumula-tor outlet tube refrigerant line coupler. See Refriger-ant Line Coupler in this group for the procedures.Install plugs in, or tape over all of the opened refrig-erant line fittings.

(7) Remove the screw that secures the suction anddischarge line manifold to the compressor. Installplugs in, or tape over all of the opened refrigerantline fittings.

(8) Remove the suction and discharge line assem-bly from the vehicle.

INSTALLATION(1) Remove the tape or plugs from the suction and

discharge line manifold and the compressor. Installthe suction and discharge line manifold to the com-pressor. Tighten the mounting screw to 22 N·m (200in. lbs.).

(2) Remove the tape or plugs from the refrigerantline fittings on the suction line and the accumulatoroutlet tube. Connect the suction line to the accumu-lator outlet tube refrigerant line coupler. See Refrig-erant Line Coupler in this group for the procedures.

Fig. 16 Suction and Discharge Line Remove/Install -Typical



(3) Remove the tape or plugs from the refrigerantline fittings on the discharge line and the condenserinlet tube. Connect the discharge line refrigerant linecoupler to the condenser inlet tube. See RefrigerantLine Coupler in this group for the procedures.

(4) Install the bolt that secures the discharge linesupport bracket to the compressor. Tighten the boltto 28 N·m (21 ft. lbs.).

(5) Plug in the wire harness connector to the highpressure cut-off switch.

(6) Connect the battery negative cable.(7) Evacuate the refrigerant system. See Refriger-


(8) Charge the refrigerant system. See RefrigerantSystem Charge in this group for the procedures.

COMPRESSORThe compressor may be removed and repositioned

without disconnecting the refrigerant lines or dis-charging the refrigerant system. Discharging is notnecessary if servicing the compressor clutch or clutchcoil, the engine, the cylinder head, or the generator.


REMOVAL(1) Recover the refrigerant from the refrigerant



(3) Remove the serpentine drive belt. Refer toGroup 7 - Cooling System for the procedures.

(4) Unplug the compressor clutch coil wire harnessconnector.

(5) Remove the suction and discharge refrigerantline manifold from the compressor. See Suction andDischarge Line in this group for the procedures.Install plugs in, or tape over all of the opened refrig-erant fittings.

(6) Remove the four bolts that secure the compres-sor to the mounting bracket (Fig. 17).

(7) Remove the compressor from the mountingbracket.

INSTALLATION

NOTE: If a replacement compressor is beinginstalled, be certain to check the refrigerant oillevel. See Refrigerant Oil Level in this group for theprocedures. Use only refrigerant oil of the type rec-ommended for the compressor in the vehicle.

(1) Install the compressor to the mounting bracket.Tighten the four mounting bolts to 28 N·m (21 ft.lbs.).

(2) Remove the tape or plugs from all of theopened refrigerant line fittings. Install the suctionand discharge line manifold to the compressor. SeeSuction and Discharge Line in this group for the pro-cedures.

(3) Install the serpentine drive belt. Refer toGroup 7 - Cooling System for the procedures.

(4) Plug in the compressor clutch coil wire harnessconnector.




COMPRESSOR CLUTCHThe refrigerant system can remain fully-charged

during compressor clutch, pulley, or coil replacement.The compressor clutch can be serviced in the vehicle.


cable.(2) Remove the serpentine drive belt. Refer to

Group 7 - Cooling System for the procedures.(3) Unplug the compressor clutch coil wire harness

connector.(4) Remove the four bolts that secure the compres-

sor to the mounting bracket.

Fig. 17 Compressor Remove/Install - Typical



(5) Remove the compressor from the mountingbracket. Support the compressor in the engine com-partment while servicing the clutch.

(6) Insert the two pins of the spanner wrench(Special Tool C-4489) into the holes of the clutchplate. Hold the clutch plate stationary and removethe hex nut (Fig. 18).

(7) Remove the clutch plate with a puller (SpecialTool C-6461) (Fig. 19).

(8) Remove the compressor shaft key and theclutch shims.

(9) Remove the external front housing snap ringwith snap ring pliers (Fig. 20).

(10) Install the lip of the rotor puller (Special ToolC-6141-1) into the snap ring groove exposed in theprevious step, and install the shaft protector (SpecialTool C-6141-2) (Fig. 21).

(11) Install the puller through-bolts (Special ToolC-6461) through the puller flange and into the jaws ofthe rotor puller and tighten (Fig. 22). Turn the pullercenter bolt clockwise until the rotor pulley is free.

Fig. 18 Clutch Nut Remove

Fig. 19 Clutch Plate Remove

Fig. 20 External Snap Ring Remove

Fig. 21 Shaft Protector and Puller

Fig. 22 Install Puller Plate



(12) Remove the screw and retainer from theclutch coil lead wire harness on the compressor fronthousing (Fig. 23).

(13) Remove the snap ring from the compressorhub and remove the clutch field coil (Fig. 24). Slidethe clutch field coil off of the compressor hub.

INSPECTIONExamine the friction surfaces of the clutch pulley

and the front plate for wear. The pulley and frontplate should be replaced if there is excessive wear orscoring.

If the friction surfaces are oily, inspect the shaftand nose area of the compressor for oil. Remove thefelt from the front cover. If the felt is saturated withoil, the shaft seal is leaking and the compressor mustbe replaced.

Check the clutch pulley bearing for roughness orexcessive leakage of grease. Replace the bearing, ifrequired.

Fig. 23 Clutch Coil Lead Wire Harness

Fig. 24 Clutch Field Coil Snap Ring Remove

INSTALLATION(1) Install the clutch field coil and snap ring.(2) Install the clutch coil lead wire harness retain-

ing clip on the compressor front housing and tightenthe retaining screw.

(3) Align the rotor assembly squarely on the frontcompressor housing hub.

(4) Install the pulley bearing assembly with theinstaller (Special Tool C-6871) (Fig. 25). Thread theinstaller on the shaft, then turn the nut until thepulley assembly is seated.

(5) Install the external front snap ring with snapring pliers. The bevel side of the snap ring must befacing outward. Press the snap ring to make sure itis properly seated in the groove.

CAUTION: If the snap ring is not fully seated in thegroove it will vibrate out, resulting in a clutch fail-ure and severe damage to the front housing of thecompressor.

(6) Install the compressor shaft key and the origi-nal clutch shims on the compressor shaft.

(7) Install the clutch plate with the driver (SpecialTool C-6463) (Fig. 26). Install the shaft hex nut andtighten to 14.4 N·m (10.5 ft. lbs.).

(8) Check the clutch air gap with a feeler gauge(Fig. 27). If the air gap does not meet the specifica-tion, add or subtract shims as required. The air gapspecification is 0.41 to 0.79 millimeter (0.016 to 0.031inch). If the air gap is not consistent around the cir-cumference of the clutch, lightly pry up at the mini-mum variations. Lightly tap down at the points ofmaximum variation.

Fig. 25 Clutch Pulley Install



NOTE: The air gap is determined by the spacershims. When installing an original, or a new clutchassembly, try the original shims first. When install-ing a new clutch onto a compressor that previouslydid not have a clutch, use 1.0, 0.50, and 0.13 milli-meter (0.040, 0.020, and 0.005 inch) shims from theclutch hardware package that is provided with thenew clutch.

(9) Reverse the remaining removal procedures tocomplete the installation.

CLUTCH BREAK-INAfter a new compressor clutch has been installed,

cycle the compressor clutch approximately twentytimes (five seconds on, then five seconds off). Duringthis procedure, set the heater-A/C control to theRecirculation Mode, the blower motor switch in thehighest speed position, and the engine speed at 1500

Fig. 26 Clutch Plate Driver

Fig. 27 Check Clutch Air Gap

to 2000 rpm. This procedure (burnishing) will seatthe opposing friction surfaces and provide a highercompressor clutch torque capability.

COMPRESSOR CLUTCH RELAY(1) Disconnect and isolate the battery negative

cable.(2) Remove the cover from the Power Distribution

Center (PDC) (Fig. 28).

(3) Refer to the label on the PDC for compressorclutch relay identification and location.

(4) Unplug the compressor clutch relay from thePDC.

(5) Install the compressor clutch relay by aligningthe relay terminals with the cavities in the PDC andpushing the relay firmly into place.

(6) Install the PDC cover.(7) Connect the battery negative cable.(8) Test the relay operation.

LIQUID LINEAny kinks or sharp bends in the refrigerant plumb-

ing will reduce the capacity of the entire air condi-tioning system. Kinks and sharp bends reduce theflow of refrigerant in the system. A good rule for theflexible hose refrigerant lines is to keep the radius ofall bends at least ten times the diameter of the hose.In addition, the flexible hose refrigerant lines shouldbe routed so they are at least 80 millimeters (3inches) from the exhaust manifold.

High pressures are produced in the refrigerant sys-tem when the air conditioning compressor is operat-ing. Extreme care must be exercised to make surethat each of the refrigerant system connections ispressure-tight and leak free. It is a good practice toinspect all flexible hose refrigerant lines at least once

Fig. 28 Power Distribution Center



a year to make sure they are in good condition andproperly routed.





(3) Remove the plastic clip that secures the liquidline to the accumulator outlet tube near the dashpanel (Fig. 29).

(4) Disconnect the liquid line refrigerant line cou-pler from the evaporator inlet tube. See RefrigerantLine Coupler in this group for the procedures. Installplugs in, or tape over all of the open refrigerant fit-tings.

(5) Disconnect the liquid line from the condenseroutlet tube refrigerant line coupler. See RefrigerantLine Coupler in this group for the procedures. Installplugs in, or tape over all of the open refrigerant fit-tings.

Fig. 29 Liquid Line Remove/Install

(6) Remove the liquid line from the plastic clipthat secures it to the right inner fender shield.

(7) Remove the liquid line from the vehicle.

INSTALLATION(1) Remove the tape or plugs from the fittings on

the condenser outlet tube and the condenser end ofthe liquid line. Connect the liquid line to the con-denser outlet tube refrigerant line coupler. SeeRefrigerant Line Coupler in this group for the proce-dures.

(2) Remove the tape or plugs from the fittings onthe evaporator end of the liquid line and the evapo-rator inlet tube. Connect the liquid line refrigerantline coupler to the evaporator inlet tube. See Refrig-erant Line Coupler in this group for the procedures.

(3) Install the plastic clip that secures the liquidline to the accumulator outlet tube near the dashpanel.

(4) Install the liquid line into the clip that securesit to the right inner fender shield.

(5) Connect the battery negative cable.(6) Evacuate and charge the refrigerant system.

See Refrigerant System Evacuate and RefrigerantSystem Charge in this group for the procedures.

FIXED ORIFICE TUBE





(3) Disconnect the liquid line from the condenseroutlet tube refrigerant line coupler. See RefrigerantLine Coupler in this group for the procedures. Installa plug in, or tape over the opened condenser outlettube fitting.

(4) Remove the fixed orifice tube from the discon-nected end of the liquid line using a needle nose pli-ers. Note the orientation of the fixed orifice tube forcorrect reinstallation.

INSTALLATION(1) Install the fixed orifice tube in the liquid line.

Be certain that it is oriented correctly within therefrigerant system flow (Fig. 30).

(2) Remove the tape or plug from the condenseroutlet tube fitting. Connect the liquid line to the con-denser outlet tube refrigerant line coupler. See



Refrigerant Line Coupler in this group for the proce-dures.

(3) Evacuate the refrigerant system. See Refriger-ant System Evacuate in this group for the proce-dures.



LOW PRESSURE CYCLING CLUTCH SWITCH


cable.(2) Unplug the wire harness connector from the

low pressure cycling clutch switch on the top of theaccumulator (Fig. 31).

(3) Unscrew the low pressure cycling clutch switchfrom the fitting on the top of the accumulator.

Fig. 30 Fixed Orifice Tube - Typical

Fig. 31 Low Pressure Cycling Clutch SwitchRemove/Install - Typical

(4) Remove the O-ring seal from the accumulatorfitting and discard.

INSTALLATION(1) Lubricate a new O-ring seal with clean refrig-

erant oil and install it on the accumulator fitting.Use only the specified O-rings as they are made of aspecial material for the R-134a system. Use onlyrefrigerant oil of the type recommended for the com-pressor in the vehicle.

(2) Install and tighten the low pressure cyclingclutch switch on the accumulator fitting. The switchshould be hand-tightened onto the accumulator fit-ting.

(3) Plug the wire harness connector into the lowpressure cycling clutch switch.


ACCUMULATOR





(3) Unplug the wire harness connector from thelow pressure cycling clutch switch.

(4) Remove the plastic clip that secures the liquidline to the accumulator outlet tube near the dashpanel.

(5) Loosen the screw that secures the accumulatorretaining band to the support bracket on the dashpanel (Fig. 32).

Fig. 32 Accumulator Remove/Install



(6) Disconnect the suction line from the accumula-tor outlet tube refrigerant line coupler. See Refriger-ant Line Coupler in this group for the procedures.Install plugs in, or tape over all of the opened refrig-erant fittings.

(7) Disconnect the accumulator inlet tube refriger-ant line coupler from the evaporator outlet tube. SeeRefrigerant Line Coupler in this group for the proce-dures. Install plugs in, or tape over all of the openedrefrigerant fittings.

(8) Pull the accumulator and retaining band unitforward until the screw in the band is clear of theslotted hole in the support bracket on the dash panel.

(9) Remove the accumulator from the vehicle.

INSTALLATION(1) Install the accumulator and retaining band as

a unit by sliding the screw in the band into the slot-ted hole in the support bracket on the dash panel.

(2) Remove the tape or plugs from the refrigerantline fittings on the accumulator inlet tube and theevaporator outlet tube. Connect the accumulator inlettube refrigerant line coupler to the evaporator outlettube. See Refrigerant Line Coupler in this group forthe procedures.

(3) Tighten the accumulator retaining band screwto 4.5 N·m (40 in. lbs.).

(4) Remove the tape or plugs from the refrigerantline fittings on the suction line and the accumulatoroutlet tube. Connect the suction line to the accumu-lator outlet tube refrigerant line coupler. See Refrig-erant Line Coupler in this group for the procedures.

(5) Install the plastic clip that secures the liquidline to the accumulator outlet tube near the dashpanel.

(6) Plug the wire harness connector into the lowpressure cycling clutch switch.




NOTE: If the accumulator is replaced, add 120 mil-liliters (4 fluid ounces) of refrigerant oil to therefrigerant system. Use only refrigerant oil of thetype recommended for the compressor in the vehi-cle.

CONDENSER


CAUTION: Before removing the condenser, note thelocation of each of the radiator and condenser airseals. These seals are used to direct air through thecondenser and radiator. The air seals must be rein-stalled in their proper locations in order for the airconditioning and engine cooling systems to per-form as designed.




(3) Remove the three retainers that secure theupper condenser air seal to the grille panel andremove the upper air seal (Fig. 33).

(4) Remove the two screws that secure the uppercondenser mounting brackets to the top of the grillepanel.

(5) Reach through the right side of the grille panelopening from the front of the vehicle to remove thescrews that secure the condenser inlet jumper tubeand outlet jumper tube block fittings to the con-denser. Install plugs in, or tape over all of the openedrefrigerant line fittings.

(6) Remove the three retainers that secure thelower condenser air seal to the passenger side framerail and the bottom of the grille panel and removethe lower air seal.

(7) Remove the two screws that secure the lowercondenser mounting bracket to the bottom of thegrille panel.

(8) Remove the three screws on each side of theradiator that secure the radiator mounting bracketsto the sides of the grille panel.

(9) Tilt the radiator and shroud unit back towardsthe engine. Use care to prevent the cooling fan bladesfrom damaging the radiator fins.

(10) Carefully lift the condenser out of the vehicle.

INSTALLATION(1) Carefully position the condenser in the vehicle.(2) Install and tighten the two screws that secure

the upper condenser mounting brackets to the top ofthe grille panel. Tighten the screws to 2.2 N·m (20 in.lbs.).

(3) Align the radiator mounting brackets to thesides of the grille panel. Install the six screws thatsecure the radiator and shroud unit to the grillepanel. Tighten the screws to 8 N·m (72 in. lbs.).

(4) Install the upper condenser air seal to the topof the grille panel with three retainers.

(5) Remove the tape or plugs from the condenserand the inlet and outlet jumper tube refrigerant lineblock fittings. Reach through the grille opening from



Fig. 33 Condenser Remove/Install

the front of the vehicle to install the inlet and outletjumper tube block fittings to the condenser with twoscrews. Tighten the mounting screws to 12 N·m (105in. lbs.).

(6) Install the two screws that secure the lowercondenser bracket to the bottom of the grille panel.Tighten the screws to 2.2 N·m (20 in. lbs.).

(7) Install the lower condenser air seal to the bot-tom of the grille panel and the passenger side framerail with three retainers.



(10) Charge the refrigerant system. See Refriger-ant System Charge in this group for the procedures.

NOTE: If the condenser is replaced, add 30 millili-ters (1 fluid ounce) of refrigerant oil to the refriger-ant system. Use only refrigerant oil of the typerecommended for the compressor in the vehicle.

VACUUM CHECK VALVE(1) Unplug the heater-A/C vacuum supply line con-

nector at the vacuum check valve near the intakemanifold vacuum adapter fitting.

(2) Note the orientation of the check valve in thevacuum supply line for correct reinstallation.

(3) Unplug the vacuum check valve from the vac-uum supply line fittings.

(4) Reverse the removal procedures to install.



VACUUM RESERVOIR(1) Remove the battery and battery tray from the

engine compartment. Refer to Group 8A - Battery forthe procedures.

(2) Unplug the vacuum supply line connector fromthe vacuum reservoir (Fig. 34).

(3) Remove the one screw that secures the reser-voir to the inner fender panel under the battery trayand behind the right front wheel house.

(4) Remove the vacuum reservoir from the enginecompartment.

(5) Reverse the removal procedures to install.Tighten the reservoir mounting screw to 1 N·m (10in. lbs.).

BLOWER MOTOR

REMOVAL(1) Remove the battery from the battery tray.

Refer to Group 8A - Battery for the procedures.(2) Remove the three screws that secure the Pow-

ertrain Control Module (PCM) to the mountingbracket on the engine compartment side of the dashpanel. Move the PCM away from the blower motoropening in the dash panel (Fig. 35).

(3) Unplug the blower motor wire harness connec-tor (Fig. 36).

(4) Remove the three screws that secure the blowermotor and wheel assembly to the heater-A/C housing.

(5) Rotate and tilt the blower motor unit as neededfor clearance to remove the blower motor and wheelfrom the heater-A/C housing.

INSTALLATION(1) Align and install the blower motor and wheel

assembly into the heater-A/C housing.(2) Install and tighten the three screws that secure

the blower motor and wheel assembly to the heater-A/C housing. Tighten the mounting screws to 2.2N·m (20 in. lbs.).

(3) Plug in the blower motor wire harness connector.

Fig. 34 Vacuum Reservoir Remove/Install

(4) Position the PCM to the mounting bracket onthe dash panel. Install and tighten the three screwsthat secure the PCM to the dash panel mountingbracket.

(5) Install the battery in the battery tray. Refer toGroup 8A - Battery for the procedures.

HEATER-A/C CONTROL

WARNING: ON VEHICLES EQUIPPED WITH AIR-BAGS, REFER TO GROUP 8M - PASSIVE RESTRAINTSYSTEMS BEFORE ATTEMPTING ANY STEERINGWHEEL, STEERING COLUMN, OR INSTRUMENTPANEL COMPONENT DIAGNOSIS OR SERVICE. FAIL-URE TO TAKE THE PROPER PRECAUTIONS COULDRESULT IN ACCIDENTAL AIRBAG DEPLOYMENTAND POSSIBLE PERSONAL INJURY.

Fig. 35 Powertrain Control Module (PCM) Remove/Install

Fig. 36 Blower Motor Remove/Install




cable.(2) Remove the glove box from the instrument

panel. Refer to Glove Box in Group 8E - InstrumentPanel Systems for the procedures.

(3) Remove the center bezel from the instrumentpanel. Refer to Instrument Panel Center Bezel inGroup 8E - Instrument Panel Systems for the proce-dures.

(4) Reach through the glove box opening to unplugthe two halves of the vacuum harness connector.

(5) Remove the four screws that secure the heater-A/C control to the instrument panel (Fig. 37).

(6) Pull the heater-A/C control assembly awayfrom the instrument panel far enough to access theconnections on the back of the control.

(7) Unplug the three wire harness connectors fromthe back of the heater-A/C control (Fig. 38).

(8) Release the temperature control cable housingflag retainer latch in the receptacle on the back of

Fig. 37 Heater-A/C Control Remove/Install

Fig. 38 Heater-A/C Control Connections

the heater-A/C control and disengage the flagretainer from the receptacle.

(9) Disengage the temperature control cable endfrom the pin of the temperature control lever on theback of the heater-A/C control.

(10) Remove the heater-A/C control from theinstrument panel.

INSTALLATION(1) Connect the temperature control cable end to

the pin of the temperature control lever on the backof the heater-A/C control.

(2) Connect the temperature control cable housingflag retainer to the receptacle on the back of theheater-A/C control.

(3) Plug the three wire harness connectors into theback of the heater-A/C control.

(4) Position the heater-A/C control in the instru-ment panel and secure it with four screws. Tightenthe screws to 2.2 N·m (20 in. lbs.).

(5) Reach through the glove box opening to plugthe two halves of the vacuum harness connector backtogether.

(6) Reinstall the glove box in the instrumentpanel. Refer to Glove Box in Group 8E - InstrumentPanel Systems for the procedures.

(7) Reinstall the instrument panel center bezelonto the instrument panel. Refer to InstrumentPanel Center Bezel in Group 8E - Instrument PanelSystems for the procedures.


BLOWER MOTOR SWITCH



(2) Using a trim stick or another suitable wideflat-bladed tool, gently pry the blower motor switchknob off of the switch stem from the front of theheater-A/C control.

(3) Remove the heater-A/C control from the instru-ment panel. See Heater-A/C Control in this group forthe procedures.



(4) Remove the two screws that secure the blowermotor switch to the rear of the heater-A/C control(Fig. 39).

(5) Remove the blower motor switch from the rearof the heater-A/C control.

(6) Reverse the removal procedures to install.Tighten the switch mounting screws to 2.2 N·m (20in. lbs.).

TEMPERATURE CONTROL CABLE



cable.(2) Disconnect the temperature control cable hous-

ing flag retainer and cable end from the back of theheater-A/C control. See Heater-A/C Control in thisgroup for the procedures.

(3) Locate the temperature control cable housingflag retainer receptacle on the bottom of the heater-A/C housing, near the passenger side of the floor pantransmission tunnel (Fig. 40). Locate the flagretainer latch release window on the side of thereceptacle. While depressing the flag retainer latchthrough the release window, use a trim stick oranother suitable wide flat-bladed tool to gently prythe cable housing flag retainer out of the receptacle.

Fig. 39 Blower Motor Switch Remove/Install

(4) Remove the screw that secures the blend-airdoor lever to the blend-air door pivot shaft.

(5) Pull the blend-air door lever down from theheater-A/C housing to remove it from the blend-airdoor pivot shaft.

(6) Remove the blend-air door lever and tempera-ture control cable from the heater-A/C housing as aunit.

(7) Remove the push nut that secures the temper-ature control cable end to the pin on the blend-airdoor lever.

(8) Remove the temperature control cable from theblend-air door lever pin.

INSTALLATION(1) Install the blend-air door lever onto the blend-

air door pivot shaft. Be certain that the tensionspring on the bottom of the heater-A/C housing isproperly positioned against the cam formation on theblend-air door lever.

(2) Install and tighten the screw that secures theblend-air door lever to the blend-air door pivot shaft.Tighten the mounting screw to 1 N·m (10 in. lbs.).

(3) Install the temperature control cable end overthe pin on the blend-air door lever and secure it witha push nut.

(4) Snap the temperature control cable housingflag retainer into the receptacle on the bottom of theheater-A/C housing.

(5) Connect the temperature control cable housingflag retainer and cable end to the back of the heater-A/C control and reinstall the heater-A/C control tothe instrument panel. See Heater-A/C Control in thisgroup for the procedures.


Fig. 40 Temperature Control Cable Remove/Install



BLOWER MOTOR RELAY



(2) Remove the glove box from the instrumentpanel. Refer to Glove Box in Group 8E - InstrumentPanel Systems for the procedures.

(3) Locate the blower motor relay by lookingthrough the outboard side of the glove box opening inthe instrument panel. The relay and connector arejust inboard of the heater-A/C wire harness connector(Fig. 41).

(4) Unplug the blower motor relay from its wireharness connector.

(5) Install the blower motor relay by aligning therelay terminals with the cavities in the wire harnessconnector and pushing the relay firmly into place.

(6) Reinstall the glove box in the instrumentpanel. Refer to Glove Box in Group 8E - InstrumentPanel Systems for the procedures.

(7) Connect the battery negative cable.(8) Test the relay operation.

KICK COVER

WARNING: ON VEHICLES EQUIPPED WITH AIR-BAGS, REFER TO GROUP 8M - PASSIVE RESTRAINTSYSTEMS BEFORE ATTEMPTING ANY STEERINGWHEEL, STEERING COLUMN, OR INSTRUMENTPANEL COMPONENT DIAGNOSIS OR SERVICE. FAIL-

Fig. 41 Blower Motor Relay

URE TO TAKE THE PROPER PRECAUTIONS COULDRESULT IN ACCIDENTAL AIRBAG DEPLOYMENTAND POSSIBLE PERSONAL INJURY.


cable.(2) Loosen the two screws that secure the upper

half of the kick cover to the heater-A/C housingunder the passenger side end of the instrument panel(Fig. 42).

(3) Remove the two screws that secure the lowerhalf of the kick cover to the heater-A/C housing.

(4) Pull the kick cover down towards the floor panto disengage the slotted upper mounting tabs fromunder the two loosened screw heads.

(5) Remove the kick cover from the vehicle.

INSTALLATION(1) Position the slotted upper kick cover mounting

tabs under the heads of the two loosened mountingscrews on the heater-A/C housing. Tighten the screwsto 2.2 N·m (20 in. lbs.).

(2) Install the two screws that secure the lowerkick cover to the heater-A/C housing. Tighten thescrews to 2.2 N·m (20 in. lbs.).


BLOWER MOTOR RESISTOR


Fig. 42 Kick Cover Remove/Install



(1) Disconnect and isolate the battery negative cable.(2) Remove the kick cover from the heater-A/C hous-

ing. See Kick Cover in this group for the procedures.(3) Pull out the lock on the blower motor resistor

wire harness connector to unlock the connector latch(Fig. 43).

(4) Depress the latch on the blower motor resistorwire harness connector and unplug the connectorfrom the resistor.

(5) Remove the two screws that secure the resistorto the heater-A/C housing.

(6) Remove the resistor from the heater-A/C housing.(7) Reverse the removal procedures to install.

Tighten the mounting screws to 2.2 N·m (20 in lbs.).

MODE DOOR VACUUM ACTUATOR


DEFROST DOOR ACTUATOR(1) Disconnect and isolate the battery negative cable.(2) Remove the knee blocker from the instrument

panel. Refer to Knee Blocker in Group 8E - Instru-ment Panel Systems for the procedures.

(3) Unplug the two vacuum harness connectorsfrom the defrost door actuator (Fig. 44).

(4) Insert a trim stick or another suitable wideflat-bladed tool into the latch hole on the heater-A/Chousing actuator mount (Fig. 45). Gently pry theactuator latch while pulling firmly outwards on theactuator to remove the actuator from the mount.

Fig. 43 Blower Motor Resistor Remove/Install

(5) Rotate and tilt the vacuum actuator asrequired to disengage the hole on the end of theactuator link from the hooked pin on the end of thedefrost door lever.

(6) Remove the defrost door vacuum actuator fromthe vehicle.

Fig. 44 Defrost, Floor, and Panel/Demist DoorVacuum Actuators

Fig. 45 Vacuum Actuator Remove/Install - Typical




FLOOR DOOR ACTUATOR(1) Disconnect and isolate the battery negative

cable.(2) Remove the knee blocker from the instrument

panel. Refer to Knee Blocker in Group 8E - Instru-ment Panel Systems for the procedures.

(3) Unplug the vacuum harness connector from thefloor door actuator (Fig. 44).


(5) Rotate and tilt the vacuum actuator asrequired to disengage the hole on the end of theactuator link from the hooked pin on the end of thefloor door lever.

(6) Remove the floor door vacuum actuator fromthe vehicle.


PANEL/DEMIST DOOR ACTUATOR(1) Remove the defrost door actuator from the

heater-A/C housing. See Defrost Door Actuator inthis group for the procedures.

(2) Unplug the vacuum harness connector from thepanel demist/door actuator (Fig. 44).


(4) Rotate and tilt the vacuum actuator asrequired to disengage the hole on the end of theactuator link from the hooked pin on the end of thepanel/demist door lever.

(5) Remove the panel/demist door vacuum actuatorfrom the vehicle.


RECIRCULATION AIR DOOR ACTUATORA recirculation air door and vacuum actuator are

used only on models with the optional air condition-ing system.


(2) Remove the kick cover from the heater-A/Chousing. See Kick Cover in this group for the proce-dures.

(3) Unplug the vacuum harness connector from therecirculation air door actuator (Fig. 46).

(4) Insert a trim stick or another suitable wideflat-bladed tool into the latch hole on the heater-A/Chousing actuator mount (Fig. 45). Gently pry the

actuator latch while pulling firmly outwards on theactuator to remove the actuator from the mount.

(5) Rotate and tilt the vacuum actuator asrequired to disengage the hole on the end of theactuator link from the hooked pin on the end of therecirculation air door lever.

(6) Remove the recirculation air door vacuumactuator from the vehicle.


HEATER-A/C HOUSINGThe heater-A/C housing assembly must be removed

from the vehicle and the two halves of the housingseparated for service access of the heater core, evap-orator coil, blend-air door, and each of the variousmode control doors.



cable.

Fig. 46 Recirculation Air Door Vacuum ActuatorRemove/Install



(2) Remove the instrument panel from the vehicle.Refer to Instrument Panel Assembly in Group 8E -Instrument Panel Systems for the procedures.

(3) If the vehicle is not equipped with air condi-tioning, go to Step 6. If the vehicle is equipped withair conditioning, recover the refrigerant from therefrigerant system. See Refrigerant Recovery in thisgroup for the procedures.

(4) Disconnect the liquid line refrigerant line cou-pler from the evaporator inlet tube. See RefrigerantLine Coupler in this group for the procedures. Installplugs in, or tape over all of the opened refrigerantline fittings.

(5) Disconnect the accumulator inlet tube refriger-ant line coupler from the evaporator outlet tube. SeeRefrigerant Line Coupler in this group for the proce-dures. Install plugs in, or tape over all of the openedrefrigerant line fittings.

(6) Drain the engine cooling system. Refer toGroup 7 - Cooling System for the procedures.

(7) Disconnect the heater hoses from the heatercore tubes. Refer to Group 7 - Cooling System for theprocedures. Install plugs in, or tape over the openedheater core tubes.

(8) Unplug the heater-A/C system vacuum supplyline connector from the tee fitting near the heatercore tubes.

(9) Remove the five nuts from the heater-A/Chousing mounting studs on the engine compartmentside of the dash panel (Fig. 47). If necessary, loosenthe battery holddowns and reposition the battery foradditional access. Refer to Group 8A - Battery for theprocedures.

(10) Remove the cowl plenum drain tube from theheater-A/C housing mounting stud on the dash paneldirectly behind the engine cylinder head.

(11) Remove the floor duct from the bottom of theheater-A/C housing. See Floor Duct in this group forthe procedures.

Fig. 47 Heater-A/C Housing Remove/Install

(12) Remove the one screw that secures the heat-er-A/C housing to the plenum bracket on the passen-ger compartment side of the dash panel.

(13) Pull the heater-A/C housing down far enoughto clear the defrost/demist and fresh air ducts, andrearward far enough for the mounting studs and theevaporator condensate drain tube to clear the dashpanel holes.

(14) Remove the heater-A/C housing from the vehi-cle.

DISASSEMBLY(1) Remove the heater-A/C housing from the vehi-

cle and place it on a work bench.(2) Unplug the vacuum harness connectors from

the floor door actuator and, if the unit is so equipped,the recirculation air door actuator.

(3) Disengage the vacuum harness from any rout-ing clips located on the lower half of the heater-A/Chousing.

(4) Disengage the heater-A/C wire harness connec-tor and the blower motor relay wire harness connec-tor push-in retainers from their mounting holes onthe heater-A/C housing.

(5) Remove the blower motor and blower wheelunit from the heater-A/C housing. See Blower Motorin this group for the procedures.

(6) Carefully remove the foam seal from the flangearound the blower motor opening in the heater-A/Chousing. If the seal is deformed or damaged, it mustbe replaced.

(7) Pull the vacuum supply line and connectorthrough the foam seal on the heater core and evapo-rator coil tube mounting flange of the heater-A/Chousing (Fig. 48).

(8) If the unit is equipped with air conditioning,remove the screw that secures the clamp to the evap-orator coil tubes and remove the clamp.

(9) Carefully remove the foam seal from the heatercore and evaporator coil tube mounting flange of theheater-A/C housing. If the seal is deformed or dam-aged, it must be replaced.

Fig. 48 Heater-A/C Housing Disassembly



(10) Use a screwdriver to pry off the two snap clipsthat help secure the upper and lower heater-A/Chousing halves to each other.

(11) Remove the 14 screws that secure the upperand lower heater-A/C housing halves to each other.

(12) Carefully separate the upper heater-A/C hous-ing half from the lower half.

ASSEMBLY(1) Assemble the upper heater-A/C housing half to

the lower half. During assembly, be certain of the fol-lowing:

(a) That each of the mode door pivot shaft endsis properly engaged in its pivot hole (Fig. 49).

(b) That the blower motor venturi ring is prop-erly indexed and installed.

(c) If the unit is equipped with air conditioning,that the evaporator coil tube rubber seal is prop-erly positioned in the grooves in both the upperand lower heater-A/C housing halves.

(2) Install the 14 screws and two snap clips thatsecure the upper and lower heater-A/C housinghalves together. Tighten the screws to 2.2 N·m (20 in.lbs.).

(3) Install the blower motor and wheel unit in theheater-A/C housing. See Blower Motor in this groupfor the procedures.

(4) Install the foam seals on the flange around theblower motor opening and the heater core and evap-orator coil tube mounting flange of the heater-A/Chousing.

(5) Insert the vacuum supply line and connectorthrough the foam seal on the heater core and evapo-rator coil tube mounting flange of the heater-A/Chousing.

(6) If the unit is equipped with air conditioning,reinstall the evaporator coil tube clamp. Tighten themounting screw to 2.2 N·m (20 in. lbs.).

Fig. 49 Heater-A/C Housing Assembly

(7) Engage the heater-A/C wire harness connectorand blower motor relay wire harness connectorpush-in retainers with their mounting holes in theheater-A/C housing.

(8) Engage the vacuum harness to the routingclips and plug in the vacuum harness connector atthe floor door actuator and, if the unit is so equipped,at the recirculation air door actuator.

(9) Install the heater-A/C housing in the vehicle.

INSTALLATION(1) Position the heater-A/C housing to the dash

panel. Be certain that the evaporator condensatedrain tube and the housing mounting studs areinserted into their correct mounting holes, and thatthe openings on the top of the housing are properlyaligned with the fresh air duct and defrost/demistduct.

(2) Install and tighten the one screw that securesthe heater-A/C housing to the plenum bracket on thepassenger compartment side of the dash panel.Tighten the screw to 3.4 N·m (30 in. lbs.).

(3) Install the floor duct to the bottom of the heat-er-A/C housing. See Floor Duct in this group for theprocedures.

(4) Install the cowl drain tube onto the heater-A/Chousing mounting stud on the dash panel directlybehind the engine cylinder head.

(5) Install and tighten the five nuts onto the heat-er-A/C housing mounting studs on the engine com-partment side of the dash panel. Tighten the nuts to6.2 N·m (55 in. lbs.).

(6) If the battery was repositioned during theremoval procedure, position the battery and tightenthe holddowns. Refer to Group 8A - Battery for theprocedures.

(7) Connect the heater-A/C system vacuum supplyline connector to the tee fitting near the heater coretubes.

(8) Unplug or remove the tape from the heatercore tubes. Connect the heater hoses to the heatercore tubes and fill the engine cooling system. Refer toGroup 7 - Cooling System for the procedures.

(9) If the vehicle is not equipped with air condi-tioning, go to Step 13. If the vehicle is equipped withair conditioning, unplug or remove the tape from theaccumulator inlet tube and the evaporator outlettube fittings. Connect the accumulator inlet tube cou-pler to the evaporator outlet tube. See RefrigerantLine Coupler in this group for the procedures.

(10) Unplug or remove the tape from the liquidline and the evaporator inlet tube fittings. Connectthe liquid line coupler to the evaporator inlet tube.See Refrigerant Line Coupler in this group for theprocedures.



(11) Evacuate the refrigerant system. See Refriger-ant System Evacuate in this group for the proce-dures.

(12) Charge the refrigerant system. See Refriger-ant System Charge in this group for the procedures.

(13) Install the instrument panel in the vehicle.Refer to Group 8E - Instrument Panel Systems forthe procedures.

(14) Connect the battery negative cable.(15) Start the engine and check for proper opera-

tion of the heating and air conditioning systems.

HEATER-A/C HOUSING DOOR


BLEND-AIR DOOR(1) Remove and disassemble the heater-A/C hous-

ing. See Heater-A/C Housing in this group for theprocedures.

NOTE: If the temperature control cable was notremoved with the blend-air door lever as a unit dur-ing the instrument panel removal procedures, thelever must be removed from the blend-air doorpivot shaft before the blend-air door can beremoved from the heater-A/C housing. See Temper-ature Control Cable in this group for the proce-dures.

(2) Lift the blend-air door pivot shaft out of thepivot hole in the bottom of the lower half of the heat-er-A/C housing (Fig. 50).


PANEL/DEMIST DOOR AND LEVER(1) Remove and disassemble the heater-A/C hous-


(2) Remove the defrost and panel/demist door vac-uum actuators from the heater-A/C housing. SeeMode Door Vacuum Actuator in this group for theprocedures.

(3) Insert a screwdriver into the latch hole (Fig.51) of the panel/demist door pivot shaft to release thelatch of the panel/demist door lever, and pull thelever out of the pivot shaft from the outside of theupper half of the heater-A/C housing.

(4) Reach inside the upper half of the heater-A/Chousing and carefully flex the panel/defrost door (Fig.52) enough so that the door pivot clears the pivothole in the housing.

Fig. 50 Blend-Air Door

Fig. 51 Mode Door Lever Remove/Install - Typical

Fig. 52 Panel/Demist and Defrost Doors



(5) Remove the panel/demist door from the heater-A/C housing.


DEFROST DOOR AND LEVER(1) Remove and disassemble the heater-A/C hous-


(2) Remove the panel/demist door and lever fromthe upper heater-A/C housing. See Panel/DemistDoor and Lever in this group for the procedures.

(3) Insert a screwdriver into the latch hole (Fig.51) of the defrost door pivot shaft to release the latchof the defrost door lever, and pull the lever out of thepivot shaft from the outside of the upper half of theheater-A/C housing.

(4) Reach inside the upper half of the heater-A/Chousing and carefully flex the defrost door (Fig. 52)enough so that the door pivot clears the pivot hole inthe housing.

(5) Remove the defrost door from the heater-A/Chousing.


FLOOR DOOR AND LEVER(1) Remove and disassemble the heater-A/C hous-


(2) Remove the floor door vacuum actuator fromthe lower heater-A/C housing. See Mode Door Vac-uum Actuator in this group for the procedures.

(3) Insert a screwdriver into the latch hole (Fig.51) of the floor door pivot shaft to release the latch ofthe floor door lever, and pull the lever out of thepivot shaft from the outside of the lower half of theheater-A/C housing.

(4) Reach inside the lower half of the heater-A/Chousing and carefully flex the floor door (Fig. 53)enough so that the door pivot clears the pivot hole inthe housing.

(5) Remove the floor door from the heater-A/Chousing.


RECIRCULATION AIR DOORA recirculation air door and vacuum actuator are

used only on models with the optional air condition-ing system.

(1) Remove and disassemble the heater-A/C hous-ing. See Heater-A/C Housing in this group for theprocedures.

(2) Remove the recirculation air door vacuumactuator from the lower heater-A/C housing. SeeMode Door Vacuum Actuator in this group for theprocedures.

(3) Reach inside the lower half of the heater-A/Chousing and lift the bottom edge of the recirculationair door upwards (Fig. 54).

(4) Guide the recirculation air door lever throughthe air intake grille of the heater-A/C housing whileremoving the door from the housing.


EVAPORATOR COIL


Fig. 53 Floor Door

Fig. 54 Recirculation Air Door




(2) Lift the evaporator coil unit out of the lowerhalf of the heater-A/C housing (Fig. 55).

(3) Reverse the removal procedures to install. Becertain that the evaporator foam insulator wrap andrubber tube seal are reinstalled.

NOTE: If the evaporator is replaced, add 60 millili-ters (2 fluid ounces) of refrigerant oil to the refrig-erant system.

HEATER CORE



(2) Lift the heater core out of the lower half of theheater-A/C housing (Fig. 56).

Fig. 55 Evaporator Coil Remove/Install

(3) Reverse the removal procedures to install. Becertain that the heater core foam insulator is rein-stalled.

DUCTS AND OUTLETSOnly the demister hoses and the panel outlet bar-

rels can be removed without instrument panelassembly removal. Removal of the fresh air duct andcollar requires that the heater-A/C housing also bepartially removed. The panel outlet housings anddemister outlets are serviced only as a part of theinstrument panel or instrument panel center bezel.


Fig. 56 Heater Core Remove/Install

Instrument Panel Ducts and Outlets Remove/Install



DEFROST/DEMIST DUCT(1) Remove the instrument panel assembly from

the vehicle. Refer to Group 8E - Instrument PanelSystems for the procedures.

(2) Remove the two push-nuts that secure thedefrost/demist duct to the studs on the dash panel.

(3) Remove the defrost/demist duct from the studson the dash panel.


DEMISTER HOSES(1) Disconnect and isolate the battery negative

cable.(2) Remove the glove box from the instrument

panel to service the passenger side demister hose.Refer to Glove Box in Group 8E - Instrument PanelSystems for the procedures. Remove the knee blockerfrom the instrument panel to service the driver sidedemister hose. Refer to Knee Blocker in Group 8E -Instrument Panel Systems for the procedures.

(3) Reach through the glove box opening or thesteering column opening of the instrument panel todisconnect the ends of the demister hose from thedemister outlet and the defrost/demist duct.


FLOOR DUCT(1) Remove the instrument panel from the vehicle.

Refer to Instrument Panel Assembly in Group 8E -Instrument Panel Systems for the procedures.

(2) Remove the two screws that secure the floorduct to the bottom of the heater-A/C housing.

(3) Release the snap clip that secures the floorduct to the dash panel side of the heater-A/C housingby pushing the snap clip towards the dash panel.

(4) Slide the floor duct out from under the heater-A/C housing.

(5) Reverse the removal procedures to install.Tighten the screws to 2.2 N·m (20 in. lbs.).

Heater-A/C Housing Ducts Remove/Install

FRESH AIR DUCT AND COLLAR(1) Remove the instrument panel from the vehicle.


(2) Remove the five nuts from the heater-A/Chousing mounting studs on the engine compartmentside of the dash panel. If necessary, loosen the bat-tery holddowns and reposition the battery for addi-tional access. Refer to Group 8A - Battery for theprocedures.

(3) Remove the floor duct from the bottom of theheater-A/C housing. See Floor Duct in this group forthe procedures.

(4) Remove the one screw that secures the heater-A/C housing to the plenum bracket on the passengercompartment side of the dash panel.

(5) Push gently down on the top of the heater-A/Chousing until sufficient clearance is obtained tounsnap the fresh air duct from the top of the heater-A/C housing.

(6) Remove the fresh air duct collar from the cowlplenum panel by reaching up above the heater-A/Chousing fresh air duct opening and pulling the collardownward. The collar is retained in the cowl plenumpanel by a light snap fit.

(7) Reverse the removal procedures to install.Tighten the plenum bracket screw to 3.4 N·m (30 in.lbs.). Tighten the dash panel mounting nuts to 6.2N·m (55 in. lbs.).

PANEL DUCTS(1) Remove the instrument panel from the vehicle.


(2) Remove the demister hoses from the demisteroutlets.

(3) Remove the two screws from the center of therearward facing side of the instrument panel thatsecure the main panel duct to the instrument panelbase.

(4) Remove the one screw that secures each endpanel duct and/or the center panel duct to the instru-ment panel base.

(5) Remove the panel ducts from the instrumentpanel.

(6) Reverse the removal procedures to install.Tighten the screws to 2.2 N·m (20 in. lbs.).

PANEL OUTLET BARRELS(1) Using a trim stick or another suitable wide

flat-bladed tool, gently pry the panel outlet barrel outof the panel outlet housing. The barrel is retained bya light snap fit.

(2) To install, position the barrel in the panel out-let housing and press in firmly and equally at bothends of the barrel until it snaps into place.

Documents

HEATING AND AIR CONDITIONING - Jeepstock Jeep/1998_TJ...air conditioning, heating, and ventilating capabilities in a single unit housing mounted under the instru-ment panel. On heater-only