Here's a general outline of the process. I strongly recommend consulting a repair manual specific to your 1990 Chevy pickup model before proceeding. The steps and specifics may vary slightly depending on the exact trim and options.
Tools You'll Likely Need:
* Steering wheel removal tool: This is crucial for safely removing the steering wheel without damaging it.
* Ignition lock cylinder removal tool: This specialized tool is needed to remove the cylinder from the steering column. Often a specific key or combination of tools is required.
* Socket set and ratchets: Various sizes will be needed for removing screws and other fasteners.
* Screwdrivers (Phillips and flathead): For various screws and connectors.
* Wire connectors/crimpers (possibly): If you need to disconnect and reconnect wiring harnesses.
* New ignition lock cylinder: Make absolutely sure you get the correct one for your year, make, and model. The key must also be correctly matched.
* Penetrating oil (like PB Blaster): To help loosen any rusted or seized fasteners.
* Gloves and safety glasses: To protect yourself.
General Steps (Always refer to a repair manual for your specific truck):
1. Disconnect the Battery: This is the most important step to prevent accidental airbag deployment or short circuits. Disconnect both the negative and positive terminals.
2. Remove the Steering Wheel: Use the steering wheel removal tool according to its instructions. This is a potentially dangerous step; be extremely cautious and follow the tool's instructions precisely. You will likely need to find the alignment marks on the steering wheel and the steering column to re-install it correctly.
3. Remove the Steering Column Shroud (or Covers): This will expose the ignition lock cylinder and related components. You may need to remove several screws and clips.
4. Disconnect the Wiring Harness: Carefully disconnect the wiring harness connected to the ignition lock cylinder. Take photos or make notes to ensure correct reconnection later.
5. Remove the Ignition Lock Cylinder: This is where the specialized removal tool is essential. The process varies depending on the tool and your truck's specific design. The repair manual will guide you through this step. Expect some resistance; use the proper tools and apply force carefully and evenly.
6. Install the New Ignition Lock Cylinder: Carefully insert the new lock cylinder, ensuring it's properly aligned. Reconnect the wiring harness.
7. Reinstall the Steering Column Shroud (or Covers): Reattach the shroud and any other components you removed.
8. Reinstall the Steering Wheel: Align the steering wheel using the alignment marks, ensuring it's properly secured.
9. Reconnect the Battery: Carefully reconnect the battery terminals.
10. Test the Ignition: Try turning the key in the new ignition cylinder to ensure it works correctly.
Important Considerations:
* Airbag System: If your truck has an airbag, be extra cautious. Disconnecting the battery is crucial, but also ensure you don't damage any airbag components during the process. Consult a professional if you're uncomfortable with this aspect.
* Steering Column Lock: The steering column lock mechanism may be affected by this process. Ensure it still operates correctly after reassembly.
* Key Programming: Some newer systems require key programming after replacing the ignition cylinder. If your truck has a transponder system (immobilizer), you'll likely need to have your keys programmed by a locksmith or dealership.
This is a complex procedure. If you're not comfortable performing this repair yourself, it's best to take your truck to a qualified mechanic. Improperly performed repairs can lead to significant damage and safety hazards. Always prioritize safety and consult your repair manual for detailed instructions specific to your vehicle.
