1. Support the Hatch: This is the most crucial step. The hatch is heavy and could cause injury if it falls. Use sturdy supports, such as jack stands placed under the hatch at points designed to support its weight (avoiding any sensitive areas). Alternatively, you might be able to temporarily secure it with strong rope or straps attached to secure points inside the car. Improper support could lead to serious injury or damage.
2. Access the Motor: The location of the motor and access panel varies slightly depending on the specific Trans Am model. Generally, the motor is located within the rear hatch mechanism itself. You might find access panels inside the hatch's trim or near the hinges. You'll need to consult a repair manual specific to your 1990 Trans Am to pinpoint the exact location. The manual will show diagrams and steps.
3. Diagnose the Problem: Once you have access, carefully inspect the motor, wiring harness, and linkages.
* Motor Failure: The motor itself may be burnt out, seized, or have internal problems. This often requires replacing the entire motor.
* Wiring Issues: Check for broken wires, loose connections, or corroded terminals in the wiring harness leading to the motor. Repair or replace damaged wiring.
* Mechanical Problems: Check the linkages and gears connecting the motor to the hatch mechanism. These might be jammed, broken, or worn out. You may need to lubricate moving parts, replace broken parts, or adjust linkages.
* Fuse or Relay: Check the fuse box for a blown fuse associated with the rear hatch. Also, check for any relays related to the hatch motor's operation.
4. Repair or Replacement: Based on your diagnosis:
* Replace the Motor: If the motor is faulty, you'll need to purchase a replacement. Finding a new OEM motor might be difficult; you might need to find a used one or a compatible aftermarket alternative. Remember to disconnect the battery before any electrical work.
* Repair Wiring: Solder broken wires, crimp new connectors onto damaged wires, and clean corroded terminals. Use electrical tape or heat shrink tubing to insulate repairs.
* Repair Mechanical Issues: This might involve lubrication, part replacement, and adjustment of the linkages. You'll need the repair manual's guidance here.
5. Reassembly and Testing: Once repairs are complete, carefully reassemble everything, ensuring all linkages and connections are properly secured. Reconnect the battery and test the hatch motor.
Important Considerations:
* Repair Manual: A factory service manual is essential. It will provide detailed diagrams, specifications, and procedures.
* Safety First: Always prioritize safety. Never work under an unsupported hatch.
* Electrical Safety: Disconnect the battery before working on the electrical components to avoid shocks.
If you lack mechanical experience or are uncomfortable working on electrical systems, it's best to seek professional help from an experienced mechanic. Improper repairs can lead to further damage or injury.
