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Home >> Jeep >> 1998 >> Grand Cherokee 2WD L6-4.0L VIN S >> Repair and Diagnosis >> Wiper and Washer Systems >> Testing and Inspection >> Wiper System

Wiper System

FRONT

If the problem being diagnosed involves only the pulse wipe or wipe-after-wash modes, see the Washer System diagnosis.

WARNING: ON VEHICLES EQUIPPED WITH AIR-BAGS, REFER TO AIRBAGS SYSTEMS BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIR-BAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.

1. Disconnect and isolate the battery negative cable. Remove the circuit breaker from the junction block. Connect the battery negative cable. Turn the ignition switch to the On position. Check for battery voltage at the battery side of the circuit breaker. If OK, reinstall the circuit breaker and go to Step 2. If not OK, repair the circuit from the ignition switch as required.
2. Turn the ignition switch to the On position. Check for battery voltage at the wiper system side of the circuit breaker. If OK, go to Step 3. If not OK, replace the faulty circuit breaker.
3. Turn the ignition switch to the Off position. Disconnect and isolate the battery negative cable. Unplug the multi-function switch wire harness connector. Connect the battery negative cable. Turn the ignition switch to the On position. Check for battery voltage at the fused ignition switch output (F86) circuit cavity of the multi-function switch wire harness connector. If OK, go to Step 4. If not OK, repair the open circuit to the circuit breaker as required.
4. If the problem being diagnosed involves only the intermittent wipe feature, go to Step 5. If the problem being diagnosed involves all wiper modes, or only the Low and/or High speed modes, go to Step 7.
5. Turn the ignition switch to the Off position. Disconnect and isolate the battery negative cable. Unplug the white 24-way Body Control Module (BCM) wire harness connector. Check for continuity between the wiper switch mode sense cavities of the multi-function switch wire harness connector and the BCM white 24-way wire harness connector. There should be continuity. If OK, go to Step 6. If not OK, repair the open circuit as required.
6. Unplug the black 24-way BCM wire harness connector. Check for continuity between the windshield wiper switch signal cavities of the mufti-function switch wire harness connector and the BCM black 24-way wire harness connector. Then should be continuity. If OK, see the Intermittent Wipe Relay diagnosis. If not OK, repair the open circuit as required.
7. Check for continuity between the two wiper switch low speed output circuit cavities of the multi- function switch wire harness connector. There should be continuity. If OK, go to Step 8. If not OK, repair the open circuit as required.
8. Test the wiper switch, as described. If the switch tests OK, plug in the multi-function switch wire harness connector and go to Step 9. If not OK, replace the faulty switch and test the wiper system operation. If still not OK, go to Step 9.
9. Turn the ignition switch to the Off position. Disconnect and isolate the battery negative cable. Move the wiper module far enough to access the wiper motor wire harness connector. Measure the resistance between the ground circuit cavity of the wiper motor wire harness connector and a good ground. The meter should read zero ohms. If OK, go to Step 10. If not OK, repair the circuit to ground as required.
10. Connect the battery negative cable. Turn the ignition switch to the On position. Place the multi-function switch in the positions indicated in the tests below, and check for battery voltage at the wiper motor wire harness connector.
a. Check for battery voltage at the fused ignition switch output circuit cavity of the wiper motor wire harness connector with the wiper switch in any position. If OK, go to Step 2. If not OK, repair the open circuit as required.
b. Check for battery voltage at the wiper switch low speed output circuit cavity of the wiper motor wire harness connector with the wiper switch in tile Low position. If OK, go to Step 3. If not OK, repair the open circuit as required.
c. Check for battery voltage at the wiper switch high speed output circuit cavity of the wiper motor wire harness connector with the wiper switch in the High position. If OK, go to Step 4. If not OK, repair the open circuit as required.
d. Check for battery voltage at the wiper park switch sense circuit cavity of the wiper motor wire harness connector with the wiper switch in the Low or High position, then move the switch to the Off position. The meter should switch between battery voltage and zero volts while the wipers are cycling. The meter should read battery voltage when the switch is moved to the Off position until the wipers park, and then read a steady zero volts. If not OK, replace the faulty wiper motor.

REAR

WARNING: ON VEHICLES EQUIPPED WITH AIR-BAGS, REFER TO AIRBAGS SYSTEMS BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIR-BAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.

1. Check the fuse in the junction block. If OK, go to Step 2. If not OK, repair the shorted circuit or component as required and replace the faulty fuse.
2. Turn the ignition switch to the On position. Check for battery voltage at the fused ignition switch output circuit cavity of the rear wiper switch wire harness connector. If OK, go to Step 3. If not OK, repair the open circuit as required.
3. Turn the ignition switch to the Off position. Disconnect and isolate the battery negative cable. Remove and test the rear wiper switch. If OK, go to Step 4. If not OK, replace the faulty switch.
4. Remove the liftgate inner trim panel. Measure the resistance between the ground circuit cavity of the rear wiper motor wire harness connector and a good ground. The meter should read zero ohms. If OK, go to Step 5. If not OK, repair the circuit to ground as required.
5. Check for continuity between the liftgate ajar switch sense cavity of the rear wiper motor wire harness connector and a good ground. There should be continuity with the liftgate and/or the lift glass (if the vehicle is so equipped) open, and no continuity with the liftgate and the lift glass closed. If OK, go to Step 6. If not OK, repair the liftgate and/or the lift glass ajar circuit or switch as required.
6. Plug in the rear wiper switch wire harness connector. Connect the battery negative cable. Turn the ignition switch to the On position. Place the rear wiper switch in the Wipe position. Check for battery voltage at the rear wiper motor control circuit cavity of the rear wiper motor wire harness connector. Repeat the test for the rear wiper motor control (intermittent) circuit cavity with the rear wiper switch in the Intermittent position, then at the rear washer motor control circuit cavity with the rear wiper switch in the Wash position. In each case, the meter should read battery voltage. If OK, replace the faulty rear wiper motor. If not OK, repair the open circuit(s) as required.
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