Troubleshooting Trailer Lights That Stop Working When Running Lights Switched Turned On

Question:

All the lights work on the trailer with the running lights off but when you turn the running lights on the right bliker and brake light stop working. When you check with a test light there is power on the flasher and power on the tail light it makes no sense

asked by: Mitch

Expert Reply:

I can help you troubleshoot your trailer lights issue.

Sounds like you are having a grounding issue with the right trailer light. I would recommend to pull that light off and check the surface that its mounted to on all sides. If it isn't mounted to a good clean surface it can cause some of the issues you are describing. If the trailer has paint, rust, or corrosion in the area you may want to sand that post spot off.

Another option would be to remount the ground to a different location like the front of the trailer but since the left one is acting normal, I would start by comparing the two's surfaces and making sure they are both clean and tightly mounted.

If you continue to have issues, I would be more than happy to continue to troubleshoot this issue with you.

expert reply by: Jackie C