Tools You'll Likely Need:
* Socket set: Various sizes, including metric.
* Screwdrivers: Phillips and flathead.
* Wrench set: Possibly both metric and standard.
* Needle-nose pliers: For manipulating small parts.
* Pry tool: A plastic pry tool is best to avoid scratching the dashboard.
* New ignition switch: Ensure you get the correct one for your year and model.
* Shop rags or paper towels: To keep things clean.
* Electrical tape (optional): To help secure wiring.
* Repair manual: Absolutely essential!
General Steps (These are general guidelines and might vary slightly):
1. Disconnect the battery: This is crucial to prevent electrical shocks and short circuits. Disconnect the negative (-) terminal first.
2. Remove the steering wheel: This is often required for access, but it's a significant step involving removing the steering wheel nut and possibly the clock spring (airbag systems were not standard in 1991, but be cautious regardless). Refer to your repair manual for this procedure. Improper removal can damage the airbag system if equipped (although unlikely in a '91).
3. Access the ignition switch: This usually involves removing parts of the steering column shroud or trim pieces around the ignition. Your repair manual will show exactly what needs to be removed.
4. Remove the ignition switch: This typically involves releasing the switch from its mounting bracket. There will likely be screws and potentially a retaining clip holding it in place. There will also be several wiring connectors that you must carefully disconnect. Take pictures or make notes as you go to remember the wiring arrangement for reassembly. Pay attention to the order of the connectors.
5. Install the new ignition switch: Carefully reverse the removal process. Make sure that all the connectors are securely attached and that the switch is properly seated in its bracket.
6. Reconnect the wiring: Again, double-check the wiring connections against your notes or photos. Incorrect wiring can damage the electrical system or prevent the car from starting.
7. Reinstall the steering wheel: This is the reverse of step 2. Make absolutely sure the steering wheel is properly aligned before tightening the nut. Improper alignment can result in dangerous driving conditions.
8. Reassemble the interior trim: Put back all the parts you removed in step 3.
9. Reconnect the battery: Reconnect the positive (+) terminal last.
10. Test the ignition switch: Try the ignition and check all functions (starter, accessories, etc.) to ensure everything works correctly.
Important Considerations:
* Ignition Cylinder: The ignition cylinder (the part where you insert your key) is often a separate component from the ignition switch itself. You may or may not need to replace this as well depending on the issue.
* Professional Help: If you're not comfortable with automotive repairs, it's best to take your Mustang to a qualified mechanic. Improper installation can damage your car's electrical system or even create safety hazards.
This is a simplified overview. You absolutely must use a repair manual specific to your 1991 Ford Mustang to ensure you have the correct procedures and diagrams. The instructions will vary depending on your specific model (coupe, convertible, etc.) and options. Attempting this repair without a manual significantly increases the risk of damage or injury.
