Troubleshooting Trailer Running Light Circuit Not Functioning When Ground is Good

Question:

how clean the trailer down to the bare metal hook the ground wire to the trailer still have no running lights got bright lights and turn signals onlywhat do I need to do

asked by: Tony

Expert Reply:

Have you tested the running light circuit of the trailer wiring on your vehicle to make sure that the problem isn't on the vehicle side of the equation. Use a circuit tester like part # PTW2993 to do this. I attached a video that shows how to do this as well.

Most likely you have a blown fuse on your tow vehicle for the trailer wiring running light circuit. You can also check the connectors on both vehicles for corrosion and clean as necessary.

It could also be that you have too many running lights and you are overdrawing the circuit from your tow vehicle so none of them are coming on. You may have to go to LED taillights if this is the case.

I also attached a help article on troubleshooting trailer wiring for you to check out.

expert reply by: Jameson C