Landing and Taxi Lights Anti-collision Lights Navigation Lights Cockpit and Cabin Lights Instrument Panel Lights Click on a System Link to Start

Landing and Taxi LightsAnti-collision Lights

Navigation LightsCockpit and Cabin LightsInstrument Panel Lights

Click on a System Link to Start

Choose Your Skill Level (click on link)

First DayEntry level knowledge of electrical schematics

and systemsStill Newbie

Practical experience with electrical schematics and systems

On My OwnProficient in troubleshooting electrical systems

Welcome!Since this is your

first day on the job, you will be working with Bob and can ask him whenever you need help. He is our senior technician. Give him a click and see what he has to say.

Bob’s dialogue“Hi, I’m Bob. Good to meet you. Looks like

you and I are going to be working together. Well, hopefully I can teach you something. I have been here for 20 years now. Let me know if you have any questions or need a hand.”

Your job task…You need to click the

clipboard to find out if there are any work orders.

You can also do a short tutorial to brush up on how to read schematics. You can access this anytime you see the image to the right.

Work Order #05216Click on Broken Landing Light Task to start troubleshooting!

Diagnosing ToolsRemember, for each malfunction you have

the choice of using three tools to help you diagnose the problem… Multi-meter

Maintenance Manuals

Ask your co-worker, Bob

Let’s get started.You have your work cut out for you. Use the

schematic to do your troubleshooting. When you think you have it fixed, click on the timer to stop the simulation and see if you made the correct decision.

Remember: You’re on the clock. A reasonable time for completing this troubleshooting project is 20 minutes so keep an eye on the stop watch. Time will start when click on your first troubleshooting choice.

Landing/Taxi light SchematicPrint out this schematic to help keep track of your troubleshooting.

Master

25A

TAXI LTLDG LTCockpit SwitchCockpit Switch

+ BAT12V

Probable CausesYour choices to check out…LightsGroundCockpit switchMaster SwitchFuseBattery

Use to return to this list of probable causes.

Master

25A


+ BAT12V

Lights

Master

25A


+ BAT12V

Which tool would you like to use?

LightsWith the multi-

meter, you can check two things…Continuity across th

e lightPower on the output

side of the lightMaster

25A


+ BAT12V

Lights

Master

25A


+ BAT12V

Continuity check is good.

What next?

LightsThe multi-meter

indicates zero volts on the output side of the light.

What next?Master

25A


+ BAT12V

Ground

Master

25A


+ BAT12V


GroundThe multi-meter

shows .000 ohms through the ground wire.

What next?

Master

25A


+ BAT12V

Cockpit Switch

Master

25A


+ BAT12V


Cockpit SwitchWith the Master

switch on, there is zero volts on the output side of the Cockpit Switch.

What next?Master

25A


+ BAT12V

Master Switch

Master

25A


+ BAT12V


Master SwitchWith the Master

Switch on, there are 12 volts on the output side of the Master Switch.

What next?

Master

25A


+ BAT12V

Fuse

Master

25A


+ BAT12V


FuseWith the multi-meter

on audible tone, there is no signal heard when placed across the fuse.

What next?

Master

25A


+ BAT12V

Battery

Master

25A


+ BAT12V


BatteryThe multi-meter

shows 12 volts coming from the battery.

What next?

Master

25A


+ BAT12V

“So you think you figured it out?”From the choices below, which one did you

determine to be the problem?

Bad batteryFaulty cockpit switchBlown fuseBad element in the lightFaulty Master SwitchBad ground

Try again…Sorry, but maybe you need to re-check the circuit.

Good Job!That’s right. This landing light doesn’t work

because of a blown fuse.

How did you do? Remember your time to shoot for was 20 minutes. If you’ve finished in less time try using this simulation at one of the higher experience levels.

Good Job!Well, looks like you

are well on your way. Good work!

Bob’s Tips“Commonly when

troubleshooting electrical systems, it is usual to start with the simplest component.”

Go back

Bob’s Tips“It’s always a good

idea to take a look at the maintenance manuals for guidance. You’re multi-meter is the best tool for determining the integrity of the circuit, especially the grounds.”

Go back

Bob’s Tips“Remember, to

check for power, you need to make sure the switches are turned on. To check for continuity the switches should be off and each segment of the circuit isolated.”

Go back

Bob’s Tips“Looks like the

element in the landing light is not burned out. I’d look to see if it also has continuity.”

Go back

Bob’s Tips“Even though the

multi-meter shows a good ground connection, it’s always a good idea to go out and actually check it with your own eyes.”

Go back

Bob’s Tips“Make sure you took

the reading with the multi-meter while both switches were on. If the cockpit switch was the only one on, than continuity is all that could be checked.”

Go back

Bob’s Tips“By determining that

the voltage on the output side of the Master Switch is what it should be, you also proved that the battery is not at fault.”

Go back

Bob’s Tips“Ah ha. Just to be

sure, I would double check this by switching the multi-meter to a digital read out and see what you get. You can always go out to the bird and check it out yourself.”

Go back

Bob’s Tips“Ok, you know your

battery is good. Looks like you’re going to have to chase the lines.”

Go back

Tutorial

Back to the simulation.

Power (Voltage)• Master Switch On

– Battery Voltage• Wire connection

• Cockpit Switches On– Battery Voltage

• Wire Connection– Fuse

• Battery Voltage to and through Lights– Switches closed– Grounding– Battery Voltage– Wire Connection

• Inline Connectors

Return to tutorial title page

Electrical GroundingCorrectly grounded circuit

Inline connectors secure Corrosion Electrical shorting

Poor connections/wire termination

Lights grounded to each other Wire Connections Grounded to airframe


Components• Wire

– Capabilities• Correct rating and type

– Continuity• Shorting• Corrosion

– Insulation• Shorting• Corrosion

– Routing• Shorting


Components cont.Switches

ContinuityWire termination

Inline connectorsCorrosionWire termination


Components Cont.• Wire terminal connections

– Size– Crimp

• Technique

• Light Bulbs– Continuity

• Wire termination• Corrosion

– Capabilities• Rating and type


Components cont.Fuse

Capabilities Correct rating and type

ContinuityCorrosion


ContinuityComplete circuit through the item being

testedShorts present in the circuit

Breaks in circuit to groundBreaks in circuitCorrosion

Dissimilar metal corrosionMoisture


Battery VoltageServiced battery

Electrolyte levelCell integrity

Connected into circuitCrimp/solder fittingsCorrosion


GroundingWire termination to airframe

Crimp/solder fittingsContinuityShortsBreaks


Possible problems• Bulb burned out• Battery not properly serviced, turned on or installed• Master switch not turned on • Cockpit switches not turned on• Fuse blown, circuit breaker popped or broken• Wires broke, shorted, disconnected, improperly

routed• Circuit is not continuous

– Breaks, shorts, corrosion or wire connections not connected

• Improper circuit grounding• Switch failure• Operator error


Possible corrections• Replace bulb• Service, turn on or install battery• Turn on master switch• Turn on cockpit switches• Replace fuse, reset or replace circuit breaker• Install, connect, properly route wires• Troubleshoot Circuit with multi-meter for

– Breaks, shorts, corrosion or wire connections not connected and correct

• Properly ground the circuit• Verify switch operation and replace if necessary• Operate circuit correctly


Documents

Landing and Taxi Lights Anti-collision Lights Navigation Lights Cockpit and Cabin Lights Instrument Panel Lights Click on a System Link to Start