1. Fuses:
* Check the fuse: A blown fuse is a common cause of electrical problems. Your owner's manual will tell you which fuse is responsible for the rear wiper. Locate the fuse box (usually under the dash or in the engine bay) and inspect the fuse. If it's blown, replace it with a fuse of the same amperage.
* Look for corrosion: If the fuse appears fine, check the fuse terminals for corrosion. Clean them with a small wire brush or sandpaper if necessary.
2. Motor:
* Power to the motor: With the ignition on, check if power is getting to the wiper motor. You can use a test light or multimeter to check for voltage at the motor connector.
* Motor itself: If power is present but the motor doesn't run, the motor itself could be faulty. It might need replacement.
3. Switch:
* Switch functionality: The wiper switch might be faulty. Check for continuity through the switch with a multimeter. If it's not working properly, it needs to be replaced.
* Loose connections: Inspect the wiring and connector for the switch for loose connections or corrosion. Clean or tighten them as needed.
4. Linkage:
* Bent or broken arm: Check the wiper arm for any bends or breaks that could prevent it from moving.
* Worn out linkage: The linkage that connects the motor to the arm can wear out over time. Inspect for any signs of wear or breakage and replace if necessary.
5. Other Problems:
* Blocked washer nozzle: A blocked washer nozzle can cause the wiper blade to stick and prevent it from working properly.
* Frozen mechanism: In cold weather, the rear wiper mechanism could freeze. Try thawing it out with warm water before attempting to use it.
Troubleshooting Tips:
* Visual Inspection: Start by visually inspecting all components of the rear wiper system, looking for signs of damage or wear.
* Test for Power: Use a test light or multimeter to check for power at the motor connector. This will help narrow down the problem.
* Consult the Owner's Manual: Your owner's manual can provide detailed information about the rear wiper system and its fuse location.
If you're not comfortable troubleshooting electrical systems, it's best to take your Subaru to a qualified mechanic for diagnosis and repair.
