Here's a general outline of the process, but remember this is *not* a substitute for a proper repair manual:
1. Disconnect the Battery: This is the most crucial first step. Disconnect the negative (-) terminal first to prevent accidental shorts.
2. Steering Wheel Removal (Possibly): Depending on the access needed to the ignition switch, you might need to remove the steering wheel. This is a complex procedure involving special tools (steering wheel puller) and potentially an airbag – exercise extreme caution and consult your repair manual if this is necessary. Disconnecting the airbag requires specific procedures to prevent accidental deployment and injury.
3. Column Shroud Removal: You'll need to remove the plastic shroud that covers the steering column. This usually involves removing screws or clips.
4. Ignition Switch Access: Once the shroud is removed, you should have access to the ignition switch itself. Its location and securing method vary slightly between vehicle years and models. Your repair manual will be your best guide here. You might need to remove other components to gain full access.
5. Wiring Harness Disconnect: Carefully disconnect the wiring harness from the ignition switch. Take photos or make detailed notes of the wire connections before disconnecting to aid in reassembly.
6. Ignition Switch Removal: The ignition switch is typically held in place with screws or clips. Remove these fasteners to release the switch.
7. Installation of the New Switch: Install the new ignition switch, carefully aligning it and securing it in place with the screws or clips.
8. Wiring Harness Reconnection: Reconnect the wiring harness, ensuring all connections are secure and match your photos or notes.
9. Reassembly: Reinstall the column shroud, steering wheel (if removed), and reconnect the battery.
10. Testing: Test the new ignition switch to ensure it functions correctly.
Important Considerations:
* Airbag: If you need to remove the steering wheel, you will almost certainly be working with the airbag system. Never work on an airbag system without proper training and the correct tools. Accidental deployment can cause serious injury or death.
* Security: You may need your car's VIN number to ensure you get the correct replacement ignition switch.
* Professional Help: If you're not comfortable working on your car's electrical system or steering column, it's best to take it to a qualified mechanic. This is a job that can easily lead to costly mistakes if done incorrectly.
Again, a repair manual specific to your 1993 Toyota Previa is essential for this repair. Don't attempt this without one. Improperly replacing the ignition switch can lead to serious issues, including immobilization of your vehicle or even damage to other components.
