Troubleshooting Trailer Light That Only Works When Handled

Question:

I have a trailer that has a 4 way plug on it. The right side light is the only one that wants to work. But when I do to take the light off with it still plugged into the tow vehicle then it all works. Can you help me?????

asked by: Carter S

Expert Reply:

We can help. It sounds like there is a grounding problem with the one light on your trailer. Since the light comes on when you handle it, this suggests that the light's grounding wire (or grounding post, if it uses the post to establish the electrical ground) is not making complete and constant contact with the trailer frame.

Grounds must be made to clean bare metal, a surface free of paint, primer, grease, rust, etc. You can try sanding the mounting point for the light (or for the ground wire, if the light uses a separate white ground wire). Once you have your ground corrected you can protect that connection with dieletric grease such as # 11755.

expert reply by: Adam R