1. Preparation:
* Gather Tools: You'll need screwdrivers (Phillips and flathead), possibly sockets and ratchets, pliers, possibly a panel removal tool (to avoid scratching the interior), and possibly a wire harness connector removal tool. A new window regulator may be needed as well, depending on its condition, as the motor is often integrated into the regulator.
* Disconnect the Battery: This is crucial to prevent accidental shorts and damage to electrical components.
* Gather Parts: Obtain the correct replacement window lift motor (and regulator, if needed). Make sure it's compatible with your specific year and model.
2. Door Panel Removal:
* Remove Interior Door Panel: This usually involves removing screws around the edges of the panel, possibly some located under the armrest or door handle. Gently pry the panel away from the door using the panel removal tool, being careful not to break any clips.
3. Accessing the Window Regulator and Motor:
* Locate the Window Regulator: Once the door panel is off, you'll see the window regulator mechanism. The motor is usually attached to it.
* Disconnect Electrical Connector: Carefully disconnect the electrical connector from the motor. Take a picture before disconnecting to help remember how it goes back together.
4. Motor Replacement:
* Remove the Old Motor: This step depends on the design of your regulator. Some motors are easily unbolted, while others might require more disassembly of the regulator itself.
* Install the New Motor: Install the new motor, ensuring it's properly seated and aligned.
* Reconnect the Electrical Connector: Carefully reconnect the electrical connector, matching the wires to the correct terminals.
5. Reassembly:
* Reassemble the Regulator: Put the regulator back together, if you disassembled it.
* Reinstall the Door Panel: Carefully replace the door panel, ensuring all clips snap into place.
* Reconnect the Battery: Reconnect the battery.
6. Testing:
* Test the Window: Operate the window switch to ensure the new motor is working correctly.
Important Considerations:
* Window Regulator Condition: Inspect the window regulator for wear and tear. If it's damaged, replacing it along with the motor is advisable. A faulty regulator can cause the new motor to fail prematurely.
* Wiring: Check the wiring for any damage or fraying while you have access to it. Repair or replace damaged wires.
* Repair Manual: A repair manual specific to your vehicle is invaluable. It will provide detailed diagrams and instructions specific to your 1986 GMC Sierra. This is highly recommended to avoid damaging the door or other components.
This is a general overview. The specific steps may vary depending on your truck. If you're not comfortable with auto repair, it's best to take your vehicle to a qualified mechanic. Improper installation can lead to further damage or injury.
