Before you begin:
* Disconnect the negative battery cable. This is crucial to prevent accidental shorts and electrical damage.
* Gather your tools: You'll likely need screwdrivers (Phillips and possibly flathead), possibly sockets and wrenches, and potentially a steering wheel lock removal tool (if applicable). The repair manual will specify exactly which tools you need.
* Obtain the correct replacement ignition switch. Using the wrong part will result in failure. Make sure it's specifically for a 1990 Ford Probe GT.
General Steps (This is a simplified overview and may vary slightly depending on your specific vehicle):
1. Steering Wheel Removal (Possibly): Some procedures require removing the steering wheel to access the ignition switch. This is a complex step requiring specialized tools and knowledge to prevent damage to the airbag (if equipped) and the steering column. Only attempt this if you're comfortable and confident in your abilities, otherwise, seek professional help.
2. Column Shroud Removal: Remove the plastic shroud or cover around the steering column. This usually involves removing screws or clips.
3. Wiring Harness Disconnection: Carefully disconnect the wiring harness connected to the ignition switch. Take pictures or make detailed notes of the wiring connections before disconnecting anything to ensure you can reconnect it correctly.
4. Ignition Switch Removal: The ignition switch itself is usually held in place by screws or a retaining clip. These are often difficult to access and may require some maneuvering. The repair manual will show the exact location and method of removal.
5. Installation of the New Ignition Switch: Once the old switch is out, carefully install the new ignition switch, ensuring all the connections are securely made. Refer to your repair manual for precise placement and orientation.
6. Wiring Harness Reconnection: Reconnect the wiring harness to the new ignition switch, making sure each wire is connected to the correct terminal. Double-check this against your notes or pictures.
7. Column Shroud Reinstallation: Reinstall the column shroud.
8. Steering Wheel Reinstallation (Possibly): If you removed the steering wheel, carefully reinstall it, ensuring it's properly aligned. This is a critical step to avoid damage to the vehicle.
9. Reconnect the Negative Battery Cable: Carefully reconnect the negative battery cable.
10. Test the Ignition: Test the ignition switch to ensure it functions correctly. Check all ignition positions (accessories, start, etc.).
Important Considerations:
* This job can be complex and may require specialized tools. If you're not comfortable working on your car, it's strongly recommended that you take it to a qualified mechanic.
* Incorrect installation can lead to damage to your vehicle's electrical system or even result in injury. Proceed with caution and refer to your repair manual for precise instructions.
* Take your time and be meticulous. Rushing this process can lead to mistakes that are difficult and expensive to fix.
This is a general overview; the exact steps may differ based on your car's specific model and condition. Always refer to a repair manual specific to your 1990 Ford Probe GT for precise instructions and diagrams. Using a Haynes or Chilton repair manual is highly recommended.
