1. Identify the Problem:
* Is it completely out? This suggests a bulb, fuse, or wiring problem.
* Is it flickering? This points more towards a loose connection or a failing bulb.
* Is only one side out? This isolates the problem to one side's bulb or wiring.
2. Gather Your Tools:
* Phillips head screwdriver: To access the trunk and potentially remove light housing.
* New license plate bulb: (Usually a 194 or 168 type; check your owner's manual or online parts store for your specific model.)
* Test light or multimeter (optional but helpful): To check for power at the bulb socket.
* Gloves (optional): To keep your hands clean.
3. Access the License Plate Light:
* Open the trunk.
* Locate the license plate light(s). On most 1998 DeVille models, they're usually integrated into the trunk lid itself. You may need to remove some trim or panels to access the bulbs, depending on the configuration. Consult your owner's manual or an online repair guide with pictures if you're unsure.
* Carefully remove the light housing(s). This often involves twisting or gently prying it loose. Some models require removing screws.
4. Inspect the Bulb:
* Remove the old bulb(s). Gently twist the bulb to remove it from its socket.
* Check for damage: Look for a broken filament (the thin wire inside) or any other visible damage.
* Replace the bulb(s): Insert the new bulb(s) and twist them to secure them in the socket.
5. Check the Wiring and Fuse (If Bulb Replacement Didn't Fix the Issue):
* Inspect the wiring: Look for any broken, frayed, or corroded wires. If you find damage, you might need to repair or replace the wiring. This can be more challenging and might require soldering skills.
* Check the fuse: Consult your owner's manual to find the fuse for the license plate lights. Use a test light or multimeter to check if the fuse is blown. Replace the fuse if necessary. (Important: Always disconnect the negative battery terminal before working with fuses or electrical components.)
6. Reassemble:
* Carefully reinstall the light housing(s). Ensure it's securely fastened.
* Close the trunk.
* Test the lights.
If the problem persists after these steps:
* Consult your owner's manual: It may have specific instructions for your DeVille model.
* Search online for repair guides: Many websites and forums provide detailed instructions with pictures for specific car models.
* Take it to a mechanic: If you're uncomfortable working on your car's electrical system, a mechanic can diagnose and repair the problem.
Remember safety first! Always disconnect the negative battery terminal before working with electrical components. If you're not comfortable working on car electrical systems, it's always best to consult a professional.
