Only Running Light Circuit Works on 1999 Ford Expedition 7-Way Trailer Connector

Question:

On my 7 way plug I only have parking light and no turn light. What could be wrong?

asked by: Justin G

Expert Reply:

The problem that you have with the 7-Way on your 1999 Ford Expedition could be a dirty or corroded trailer connector. Make sure that the connector is clean and free of corrosion inside, where the wires attach, and outside on the pins themselves. Also check for loose or damaged wires and fix as needed.

If you still have problems then it could be a fuse or relay related to the tow package wiring. There are several on your Expedition:

In-cab fuse box:
Location 23 for trailer tow battery charge (12 volt circuit)

Power Distribution Box (under the hood):
Location 5 for trailer tow backup and parking lamps
Locations 19 and 20 for trailer tow turn signals and brake lights
Location 101 for trailer tow battery charge
Location 108 for electric trailer brake controller
Location 201 trailer tow park lamp relay
Location 203 trailer tow backup lamp relay
Location 302 battery charge relay