C lear vision is absolutely essential for safe driving. No one would dispute

the necessity of having good windshield wiper blades when driving in wet weather conditions. But good wipers are just as important for dry weather visibility too. Not only do they clear rain, mist, sleet and snow from the windshield, they also remove road splash, bug splatter, dust and grime (with the help of the windshield washers). Consequently, motorists should see their wipers as a critical safety system on their vehicle – something that should not be neglected but should be inspected regularly and replaced as needed to maintain optimum visibility.

Wiper blades don’t last forever. Regardless of the type of blades that are on a vehicle, they all need to be changed at regularly scheduled intervals. The natural and synthetic rubbers that are used in wiper blades age over time from exposure to heat, ozone and direct

sunlight (ultraviolet radiation). This causes the rubber to lose some of its flexibility and crack (which causes chattering and streaking). Other factors that influence wiper life include how often the wipers are used (more frequent use accelerates wear), how much dirt and grime the blades are exposed to (silica dust is abrasive and wears away the sharp square cut edge on the blades which is necessary for a clean wipe), and exposure to chemicals that may harm the blades (like some windshield solvents and cleaners).

When To ReplaceWiper blades should be replaced if they are streaking, smearing, chattering or skipping, or if the blade is torn or damaged. Ideally, the wipers should be replaced BEFORE they reach this point – which for many motorists means ONCE or even TWICE a year depending on driving and weather conditions and frequency of use.

Unfortunately, many motorists put off replacing their wiper blades until the

©2012 National Automotive Parts Association

Wipers & Glass Treatments

} Wiring Basics

} Diagnosing Electrical Problems

} Circuit Tests With a DMM

} Voltage Drop Testing

} Bad Wiring & Connectors

} Replacing a Wiring Connector

} Intermittent Wiring Faults

continued insideOne of the best times to check the blades is after washing the car. If they don’t wipe cleanly, it’s time for new blades.

Good wipers are a must for wet weather driving, especially at night when glare and road grime can obscure vision.

}  When To Replace

}  Tech Tips

}  Changes In Wiper Technology

}  Finding the Correct Replacement Blade

}  Replacing Blades

}  Glass Treatments

}  Review Questions

ISSUE 11.2012

blades are barely functional, which can create a dangerous situation if they are caught driving in a heavy downpour or other conditions that require keeping the windshield clean. A better approach is to check the blades regularly (just after washing the vehicle is a good time) or when other maintenance is performed (such as an oil change). If the wipers are chattering, streaking, cracked or not wiping cleanly, NOW is the time to replace them rather than later.

With older style wiper blades that have metal frames, there is a risk of permanently scratching the windshield if an aging blade tears away and allows the metal frame to rub against the glass.

The rear wipers on minivans, SUVs and hatchback cars are also important for good rearward visibility when backing up, when driving in heavy traffic (so you can see the vehicle behind you who is following too close or not paying attention!), and when driving on dusty gravel roads (to clear the rear glass). Rear blades also deteriorate over time, and are often found to be in poor condition. So it is important to inspect all the wipers on a vehicle, not just the ones for the windshield.

Changes In Wiper TechnologyIn recent years, wiper blades have evolved considerably. In 2000, the first frameless or “beam” style wiper blades appeared on a number of European cars. The use of this style of wiper blade gradually spread and is now found on many late model cars and trucks.

More recently, next generation “hybrid” wiper blades that offer even better performance have been introduced for both new vehicle applications and for upgrading older vehicles with traditional blades or beam blades. NAPA’s line of wiper blades includes traditional frame style blades such as NAPA AccuFit, and Bosch Micro Edge and Excel. NAPA also carries beam style blades such as NAPA Vista and Bosch Evolution for late model applications, and premium NAPA

Genesis hybrid blades that can be installed on many late model and older applications for even better wiping performance.

Traditional frame style blades can trap ice and snow during cold weather, causing them to skip and streak. One solution is to replace them with Winter Blades that enclose the frame with a thin rubber membrane. The other solution is to replace the original frame style blades with the newer beam style blades. With no frame to trap ice and snow, there is less risk of clogging and streaking.

The metal or plastic frame on a traditional wiper blade can also create wind resistance, which increases noise and lift as the speed of the vehicle goes up. Slots machined into the frame can reduce wind resistance, and small airfoils placed atop the frame may increase downforce to reduce wind lift. But even with these aids, a traditional frame style wiper is no match for the newer beam or hybrid style blades.

With beam style blades, the rubber wiping element is molded around an internal flat metal spring (or pair of springs). The spring provides the necessary support and stiffness to keep the blade straight while also allowing it to flex downward so it can follow the curvature of the windshield. The internal spring also maintains even pressure along the entire length of the blade. Some blade manufacturers even use different springs for the right and left

TECHtipsm If you have installed new wiper blades but they are not wiping cleanly, the problem may be weak wiper arms. Wiper arms can lose spring tension over time. Weak springs may not hold the wipers firmly against the windshield, allowing them to streak or lift away from the glass at highway speeds. Wiper arm spring tension can be checked with a pull gauge (like a fish scale). New arms with conventional frame style blades typically have a spring tension of around 14 Newton-meters (10.3 lbs.) while the tension on newer vehicles with flat frameless blades is typically around 17 N.m (12.5 lbs.). Tension will vary somewhat by application, the length of the arms and the size of the blades.

m Noisy wiper blades can be caused by wear and play in the wiper arm drive mechanism. The pivot points and bushings in the wiper arm linkage may be worn and loose. This can be checked by turning on the wipers, then turning off the ignition with the wipers in mid-stroke. Exert light pressure sideways against each of the wiper arms to see how much movement is in the linkage. More than a few millimeters of play probably indicates worn linkage components that need to be replaced.

m Wipers not working? A common cause for this condition is often a blown fuse. If ice or snow momentarily jam the wipers when the wipers are turned on, or while the wipers are running, it can overload the wiper motor causing the fuse to blow. Locate the fuse for the wipers and check the fuse. If the fuse is blown, replace it with one that has the SAME amp rating as the original, never a higher amp rating as this may allow dangerous overloads that could damage the wiring or wiper motor. If the fuse blows as soon as the wipers are turned on, there is a short in the wiper electrical circuit or the wiper linkage is jammed preventing the motor from turning. If the fuse holds but the wipers don’t work, there is an open in the wiper electrical circuit or the wiper motor has failed.

Frameless beam style wiper blades have many advantages over traditional wiper blades with frames.

Wipers & Glass Treatments

ISSUE 11.2012

blades so the blades can conform better to the curvature of the windshield. The low profile aerodynamic shape of beam style wiper blades also reduces wind lift and noise at highway speeds.

Beam style blades also have no exposed metal parts to rust or discolor. Some use one type of rubber for the body of the blade, and another type for the wiping surface. Others use silicone or another coating to enhance durability and reduce friction.

By comparison, NAPA’s hybrid Genesis wipers offer the best features of traditional blades and beam blades. The blade is supported by a primary and secondary stamped steel bridge. This provides maximum strength and durability while allowing increased flexibility so the blade can easily follow the curvature of the glass. The shape of the hybrid wiper bridge also improves aerodynamic downforce to hold the blade firmly against steeply sloped and curved windshields at all speeds. A graphite coating on the blade element reduces friction for a clean, smooth wiping action.

Finding the Correct Replacement BladeThough wiper blades are usually sold by length, always follow the application listing for the vehicle. Many vehicles have asymmetrical length blades, with the driver side often being longer than the passenger side. Matching the length of the original blades is critical to avoid interference problems and to assure a proper fit. Some blades are also designed for a specific side (right or left) and may have special internal features that provide greater conformability for sharply curved glass.

Adapters are not required for NAPA AccuFit wiper blades. But for others, adapters are included with the new blades so one part number can be installed on a broad range of different applications. The instructions on the package show how to use the adapters.

Replacing BladesReplacing a set of wiper blades is typically a quick and easy job on most vehicles, but it can be tricky on some depending on how the wiper blades are attached to the arms.

Basically, the wiper arm is lifted up away from the windshield until it locks in its outward position. If the arm does not lock, it must be held or propped in position so it does not snap back against the windshield (which could break the glass!). On some applications, the wipers park behind the lip of the hood which prevents the arms from being raised out away from the windshield. On these vehicles, turn on the ignition and the wipers, then shut off the ignition when the wipers are in mid-stroke so arms are clear of the hood lip.

Once the arms are away from the windshield, the attachment that holds the old blade on the arm can be released allowing the blade to be removed. There are several styles of attachments. The

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NAPA offers a large selection of replacement wiper blades.

NAPA Genesis hybrid wiper blades combine the best features of traditional and beam style wipers for improved wiping performance.

Review Questions November 2012: Wipers & Glass Treatments 1. Wiper blades need to be replaced because:

a. Sunlight and ozone can damage the rubber

b. Excessive heat can damage the rubber

c. Usage gradually wears off the wiping edge of the blades

d. All of the above

2. Compared to traditional wiper blades with metal or plastic frames, beam style blades:

a. Have more even loading across the face of the blade

b. Experience less wind lift and noise

c. Have no external frame

d. All of the above

3. Adapters are NOT required with which type of replacement blade?

a. NAPA Genesis blades

b. Icon blades

c. NAPA AccuFit blades

d. Micro Edge blades

three most common are the hook-slot connector, pin-type arm and straight-end connector.

Hook-slot connector: Swing the blade perpendicular to the arm so you can see the connector. You’ll find a tab at the connector that needs to be lifted or pushed to release the lock that holds the blade pivot in the hook slot. Once the tab is released, a firm shove toward the base of the arm will slide the blade right out of the hook slot.

Pin-type arm: Raise the arm and examine the locking tab that holds the blade onto the pin. You’ll either have to push the tab up from underneath the blade or lift the tab from the top with a screwdriver. Once the tab unlocks the pin, pull the blade assembly with a sideways motion away from the arm. The new unit may simply lock onto the pin. Sometimes, the new blades will come with an adapter that locks into the blade opening and accepts pins of different sizes.

Straight-end connector: The straight-end connector can be tricky. Sometimes you need to lift a tab on top of the existing blade with a screwdriver to clear the locking nub on the arm. You may also need to cock the old blade a few degrees

out-of-parallel with the arm to slide it off the arm’s end.

Once the old blades have been removed, the correct adapter can be attached to the new wiper blades, and the blades installed on the arms. Make sure the wipers are locked securely in place before testing the wipers.

Glass TreatmentsAnother product that can enhance wet weather visibility and driving safety is a water-repelling glass treatment such as Rain-X. Available as a liquid in a bottle, spray bottle or on pretreated wipes,

Rain-X applies a hydrophobic (water-repelling) non-stick chemical coating to the glass that repels rain, sleet and snow. It also reduces friction for easier wiping.

When droplets of rain hit the glass, they just bead up and roll off without sticking or streaking. At highway speeds, the glass may almost be self-cleaning reducing the need to use the wipers. An intermittent wiper speed rather than a steady speed may be all that’s needed to keep the windshield clear.

The glass treatment also allows easier removal of frost, ice, salt, bug splatter and grime from the windshield and other glass year-round. It works great on windshields, side windows, rear hatchback and liftgate windows, and even side mirrors.

Glass treatments such as Rain-X are inexpensive and easy to apply. For best results, the glass must be cleaned prior to application. Follow the application directions on the product and use it sparingly. Apply the glass treatment evenly, rub it in with a paper towel, let it dry then wipe off the residue.

Over time, the glass treatment will wear off and need to be reapplied. New wiper blades are also recommended for best results.

Answers: 1. d, 2. d, 3. c

Rain-X glass treatment.