1. Identify the Faulty Switch:
* Determine the symptom: Is the dome light not working when you open the door? Are the power locks not responding? Is there a specific electrical issue? This pinpoints the problem switch.
* Visual inspection: Check the door panel for obvious damage around the switch area. A broken switch might be visually apparent.
2. Gather Tools and Materials:
* New door switch: Crucial! Get the correct replacement part. The part number is usually found on the old switch or in a parts catalog (like AutoZone, Advance Auto, etc.) using your Expedition's VIN.
* Small flat-head screwdriver: For prying and potentially removing trim panels.
* Phillips head screwdriver: May be needed depending on the switch and door panel design.
* Panel removal tool (optional): These plastic tools help prevent scratching the door panel.
* Socket set (potentially): Some switches might have screws requiring sockets.
* Electrical tape (optional): For securing wires if needed.
* Shop rag or towel: To keep things clean.
3. Accessing the Door Switch:
This is the most variable step. It involves removing the inner door panel. The procedure is generally similar across doors, but details may vary slightly:
* Remove the door panel:
* Window switch: Start by lowering the window completely.
* Interior door handle: Usually, there's a screw or two hiding under a cover (sometimes a small rubber plug). Remove these.
* Door release lever: There will likely be fasteners (screws or clips) holding it in place.
* Armrest: The armrest (if present) might need to be unscrewed.
* Panel clips: The panel is held on by numerous plastic clips. Carefully pry the panel away from the door, starting at the bottom. Use your flat-head screwdriver and/or panel removal tool gently to avoid breaking the clips. Work your way around the perimeter of the panel.
* Wiring harnesses: Once the panel is loose, carefully disconnect the wiring harnesses connected to the door switch, power locks, and window regulators. Note how they are connected for reassembly.
* Locate the door switch: The switch is typically behind the door panel, often in a readily accessible location.
4. Replacing the Switch:
* Disconnect the old switch: Unplug the wiring harness from the old switch. Take pictures or make notes if needed.
* Remove the old switch: This can involve unscrewing it, popping it out of its mounting bracket, or simply unplugging it.
* Install the new switch: Connect the wiring harness to the new switch in the same way the old one was connected. Make sure it's firmly seated.
* Reinstall the door panel: Reverse the removal process carefully, ensuring all the clips are properly reattached.
5. Test the Switch:
* Close the door: Test the functionality of the switch (dome light, power locks, etc.) to ensure it's working correctly.
Important Considerations:
* Consult a repair manual: A specific repair manual for your 1998 Ford Expedition will provide detailed instructions and diagrams for your particular model. This is the best resource.
* Take pictures: As you disassemble the door panel, take pictures of each step to aid in reassembly.
* Be gentle: Avoid applying excessive force, as you could break plastic clips or damage the door panel.
* If unsure, seek professional help: If you're uncomfortable working on your vehicle, it's always best to consult a qualified mechanic.
This is a general guide. The exact steps may vary depending on the specific door and switch type. Again, a repair manual is strongly recommended for the most accurate and detailed instructions.
