bing tracking image
Q & A Icon

Troubleshooting Running Lights not Working on Trailer


I have a relatively new trailer and when ANY truck is connected to it, the running lights on trailer work for a short period of time, then blow that fuse in the truck. I think its grounding. There is a junction box on trailer hitch where breakaway battery is stored. There are three ground wires in there connected by a wire nut. One goes to the plug, one to the brake battery, and the third is attached to the frame. There is a bunch of insulation melted off the wires within an inch of the wire nut. My question my grounding issue it that area, or is it still possible that it could be a bad ground at any of the lights which each have independent grounds mounted to the frame. Its a 7 pin connector in case it matters. Just trying not to do more than I have to : Thanks in advance.


Expert Reply:

It sounds like your issue is definitely coming from a grounding issue. I would start by getting those wires cleaned up and re attached. I would suspect that there is part of that ground coming in contact with the running light circuit causing it to blow that fuse out. You can use LCD Digital Circuit Tester part # PTW2992 to find what wire is providing the running light signal on your trailer and inspect it and the ground to see where they are making contact. Or where they may be pinched together.

expert reply by:

Products Referenced in This Question

Product Page this Question was Asked From

Q & A Icon

Similar Expert Q&A Pages

See More Q&A Expert Answers >>