1. Preparation:
* Disconnect the battery: This is crucial to prevent short circuits and accidental activation of the wipers. Disconnect the negative (-) terminal first.
* Gather tools: You'll need a set of screwdrivers (likely Phillips and flathead), possibly some pliers, and possibly a socket set depending on how the switch is mounted. A shop rag is also helpful.
* Consult a repair manual: A Haynes or Chilton repair manual specific to your 1986 GMC Suburban is highly recommended. These manuals provide detailed diagrams and instructions specific to your vehicle's year and model. This is the most reliable source of information.
2. Accessing the Switch:
* Steering column removal (likely): In most vehicles of this era, the wiper switch is located within the steering column assembly. This often requires partially or fully removing the steering column shroud and possibly the steering wheel itself. The repair manual will detail this process precisely. Be extremely careful during this step, as the steering column is a critical safety component. Consider marking component positions with tape and a pen before disassembling to aid in reassembly.
* Wiring harness connector: Once you access the switch, you'll need to carefully disconnect the wiring harness connector. Take photos or make notes before disconnecting anything to aid reassembly.
3. Replacing the Switch:
* Remove the old switch: The switch is typically held in place with screws or clips. Carefully remove them to release the old switch.
* Install the new switch: Carefully insert the new wiper switch, ensuring it's properly aligned. Secure it with the screws or clips.
4. Reassembly:
* Reconnect the wiring harness: Double-check that all connectors are securely seated.
* Reinstall the steering column components: Carefully reassemble the steering column shroud and steering wheel, following the reverse order of disassembly. Refer to your repair manual for precise instructions.
* Reconnect the battery: Reconnect the battery's negative (-) terminal.
5. Testing:
* Test the wipers: Turn the ignition on and test all wiper functions (low, high, intermittent) to ensure the new switch is working correctly.
Important Considerations:
* Steering Wheel Removal: Removing the steering wheel can be tricky and potentially dangerous if not done correctly. If you are not comfortable with this, it's best to take your Suburban to a qualified mechanic.
* Airbag (if equipped): If your Suburban has an airbag, you need to be extremely careful during disassembly and reassembly to avoid accidental deployment or damage. This might require disconnecting the battery for an extended period to ensure the system is safe.
* Parts: Ensure you purchase the correct replacement wiper switch for your 1986 GMC Suburban. The part number should be verified using your vehicle's VIN or your repair manual.
This is a general overview. The specific steps will depend on your vehicle's configuration. Always consult a repair manual for detailed instructions and safety precautions before attempting this repair. If you're uncomfortable with any part of this process, it's advisable to take your vehicle to a qualified mechanic. Improperly reinstalling the steering column can be dangerous.
