1. Check the Wiper Fuse:
- Open the fuse box cover located in the rear cargo area on the driver's side.
- Identify the fuse labeled "Rear Wiper" or "WIPER R" in the fuse box diagram.
- Check if the fuse is blown by visually inspecting it. A blown fuse will have a broken filament inside.
- If the fuse is blown, replace it with a new fuse of the same amperage rating.
2. Inspect Wiper Motor:
- Open the rear tailgate and remove the interior trim panel that covers the rear wiper motor.
- Check if the wiper motor looks visually damaged or corroded.
- Disconnect the electrical connector from the wiper motor and use a multimeter to test if the motor is receiving power when the rear wiper switch is turned on.
3. Test Wiper Linkage:
- Check the wiper linkage that connects the motor to the wiper arm.
- Ensure that the linkage components are intact and not damaged or misaligned.
- Try to move the wiper arm by hand to see if it encounters any resistance.
4. Check Wiring:
- Follow the wiring harness from the wiper motor to the rear wiper switch.
- Look for any loose connections, damaged wires, or corrosion along the wiring.
- Check the continuity of the wires using a multimeter to ensure proper electrical flow.
5. Inspect Rear Wiper Switch:
- Remove the steering column covers to access the rear wiper switch.
- Disconnect the electrical connector from the switch and test its functionality using a multimeter.
- Check if the switch is sending the appropriate signals when the wiper control is activated.
6. Scan for Diagnostic Trouble Codes (DTCs):
- Connect an OBD-II scanner to the vehicle's diagnostic port.
- Check for any stored DTCs related to the rear wiper system.
- This can provide additional information about the specific issue causing the malfunction.
7. Seek Professional Help:
- If you encounter difficulties in troubleshooting or repairing the rear wiper, it's recommended to seek assistance from a qualified mechanic or automotive electrician.
By following these steps, you can narrow down the possible causes of the malfunctioning rear wiper in your 2005 Envoy. If you lack the tools or expertise necessary for electrical troubleshooting, it is advisable to consult with a professional to ensure proper diagnosis and repair.
