* Bad Bulb: Even new bulbs can be faulty. Try a different new bulb to rule this out.
* Bad Socket: The bulb socket itself might be damaged or corroded. Inspect the socket for any signs of damage, corrosion, or broken contacts. Clean the socket with a contact cleaner if necessary.
* Wiring Issue: There could be a break or short in the wiring leading to the license plate lights. Trace the wires from the bulb socket back to the fuse box and check for any visible damage.
* Fuse: A blown fuse is a common culprit. Check your owner's manual to locate the fuse for the license plate lights and test it with a fuse tester or by visually inspecting it for a broken filament.
* Wiring harness: The wiring harness, particularly if it's subjected to the elements or rubbing against other parts, can be damaged.
* Grounding Problem: A poor ground connection can prevent the lights from working. Check the ground wire connecting to the chassis.
* Faulty switch: Less likely, but possible there is an issue with a switch which affects the license plate lights.
Troubleshooting Steps:
1. Check the fuse: This is the easiest and quickest thing to do.
2. Inspect the bulb socket: Look for corrosion, damage, or loose connections.
3. Test with a known good bulb: This isolates whether it's the bulb or something else.
4. Inspect the wiring: Look for any visible damage along the wire from the socket to the fuse box.
5. Check the ground connection: Ensure a good ground connection to the chassis.
If you've checked all of these and the problem persists, it's best to consult a qualified mechanic or auto electrician. They have the tools and experience to diagnose more complex electrical issues.
