1. Fuses: Check the fuse box (usually under the hood or inside the cabin) for a blown fuse related to the rear wiper. Your owner's manual will show you the fuse diagram and which fuse controls the rear wiper motor.
2. Wiper Motor: The motor itself might be faulty. This requires access to the rear of the vehicle to test the motor directly (often involves removing the interior trim panel). You can try tapping the motor lightly while someone operates the switch; a click or whir might indicate a problem with the motor's brushes.
3. Wiring: Check the wiring harness connecting the wiper motor to the switch and the fuse box for any breaks, corrosion, or loose connections. This is often the culprit, especially if the wiring runs through areas prone to flexing or moisture.
4. Switch: The rear wiper switch itself could be faulty. This would require replacing the switch.
5. Linkage: The linkage connecting the motor to the wiper arm might be broken, seized, or dislodged. This is easily visible by inspecting the rear wiper assembly.
6. Washer Fluid: While less likely to directly cause wiper malfunction, ensure you have sufficient washer fluid. Some systems won't operate the wiper if the reservoir is very low.
Troubleshooting Steps:
1. Start with the easiest checks: Fuses and washer fluid level.
2. Visual inspection: Check the linkage and wiring for obvious damage.
3. Use a multimeter (optional but recommended): A multimeter can be used to test the power at the fuse, the switch, and the motor to determine where the circuit is broken.
4. Consult a repair manual: A repair manual specific to your 2002 Jeep Liberty will provide detailed diagrams and troubleshooting steps.
If you're not comfortable working on your car yourself, take it to a qualified mechanic. Attempting repairs without the proper knowledge could cause further damage.
