Troubleshooting Trailer Running Lights Not Working

Question:

Cant get my trailer running lights on but stop light and turn signals work

asked by: T.mickens

Expert Reply:

First thing you want to do is test the trailer connector of your vehicle with a circuit test like part # PTW2993 for voltage on the running light circuit. See the diagrams of the various trailer connectors in the FAQ article I attached.

If voltage isn't there most likely it's a blown fuse or relay. Check your fuse box legend or owners manual to determine the trailer wiring fuses and replace as necessary. Corrosion on the running light circuit pin of your wiring harness could also cause this problem. Clean as necessary.

If the circuit is working fine on your vehicle then the problem lies in your trailer wiring. I would first clean the connector of your trailer as corrosion there could cause the problem. On the front and backside of the connector there could be corrosion so check both places. Next, you will want to trace the wiring of this circuit from the connector to the light assemblies looking for any cut or exposed wire that could cause a short and fix as necessary.

I attached an FAQ on troubleshooting trailer wiring for you to check out as well.

expert reply by: Jameson C