The parking, taillight, license plate, and brake lights are not working?

1998 LINCOLN TOWN CAR

170,000 MILES • 4.6L • V8 • 2WD • AUTOMATIC

CLEEZYWEEZY33

MEMBER
2 POSTS

It all started when I noticed my car listed above car hoopty series’ taillights weren’t working. Then I noticed the brake lights weren’t working either although the third brake light does. I changed the multi-function switch and the turn signals and hazards both work. Headlights work but no parking lights whatsoever. I changed the brake light switch and noticed the harness was melted so I swapped that out too. I’ve pulled every fuse and none are blown. So here is what I got:

Not working:
Parking lights
Taillights
Lower brake lights (third brake light works)
License plate light

What does work:
Headlights
Reverse lights
Turn signals
Hazards

Mar 29, 2025 at 6:59 PM

STEVE W.

✓ASE Certified Mechanic
15,200 POSTS

As shown in the attached you can see the brown wire is the feed to all of the tail and marker lights that are out. From the melted harness and light failure, it sounds like the lighting control module has likely burnt out from a load on it. The brake lights are all fed from the same switch and fuse. So that switch and fuse are OK. It then feeds the dark green that goes through the switch and to the lights on 2 different circuits.
You say it has nonstock taillights? If so, then it is possible that something in them shorted and caused an overload.

Images (Click to enlarge)

Professional Diagram for 2CarPros Members
Click here to log in and view diagram.

Mar 29, 2025 at 8:17 PM

Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.