Tools You'll Likely Need:
* Socket set (metric)
* Ratchet and extensions
* Screwdrivers (Phillips and possibly flathead)
* Pliers
* Wire cutters/strippers (if replacing wiring harness connector)
* Torque wrench (recommended)
* Possibly a trim removal tool to avoid scratching the interior
* New rear wiper motor
* Shop rags or paper towels
Procedure (General Steps - Consult your repair manual for specifics):
1. Disconnect the Battery: This is crucial to prevent accidental shorts and shocks. Disconnect the negative (-) terminal first.
2. Access the Motor: This is the most variable part. You'll likely need to remove the interior trim panel in the rear hatch/liftgate. This often involves unscrewing panels, possibly popping off plastic clips (use trim tools to avoid damage), and possibly disconnecting the rear hatch light. The motor is usually located under the rear hatch trim, near the wiper arm assembly. Your repair manual will show you precisely where it is located.
3. Disconnect the Wiper Motor:
* Electrical Connector: Carefully disconnect the electrical connector from the wiper motor. Take a picture beforehand to remember how it goes back together.
* Mechanical Linkage: Disconnect the linkage connecting the motor to the wiper arm. This usually involves removing a nut or bolt, sometimes with a clip or retainer to secure it.
4. Remove the Wiper Motor: Once the electrical connector and mechanical linkage are disconnected, the motor itself may be secured with bolts or screws. Carefully remove these fasteners and remove the motor.
5. Install the New Motor:
* Carefully install the new motor, ensuring it's seated correctly.
* Reattach the mounting bolts or screws, tightening them to the manufacturer's specified torque.
* Reconnect the mechanical linkage, ensuring it's properly aligned and secured.
* Reconnect the electrical connector.
6. Reassemble: Carefully put back all the interior trim panels, ensuring all clips and fasteners are correctly secured.
7. Reconnect the Battery: Reconnect the battery's negative (-) terminal.
8. Test the Wiper: Turn on the rear wiper to test its functionality.
Important Considerations:
* Repair Manual: A repair manual specific to your 2003 Pontiac Montana is invaluable. It will have diagrams, torque specifications, and step-by-step instructions tailored to your vehicle.
* Rust: In older vehicles, rust can make removing fasteners difficult. Use penetrating oil (like PB Blaster) to help loosen them.
* Clips: Be careful when removing plastic trim clips. They can easily break.
* Wiring: If the wiring harness is damaged, you may need to replace the connector or even splice in new wire.
This is a general outline. The exact steps will vary depending on your vehicle. Always refer to your repair manual for the most accurate and detailed instructions. If you're uncomfortable performing this repair yourself, take it to a qualified mechanic.
