Left Hand Tail Light Fuse Blows on Tow Vehicle with Trailer Attached

Updated 11/06/2018 | Published 11/05/2018

Question:

Kept having a problem with blowing fuses on the running lights, with a recently purchased trailer. Decided to install a new wiring harness and lights which solved the running lights issue but now the left hand blinker is blowing fuses. Trailer is grounded in 3 spots, a ground of each light and the harness itself is grounded to the trailer near the tongue. Any ideas on what the problem could be?

asked by: Owen

Expert Reply:

When a fuse on the tow vehicle associated with the trailer lights blows this means that you have an overdraw. The overdrawn is most likely associated with a short in the wire. The short could be anywhere from the trailer wiring harness where it connects to the vehicle's tail light all the way back to the tail light on the trailer. You will need to trace this wire back while checking for breaks in order to find the sort. I would also pay special attention to the trailer connectors to make sure none of the pins are bent or are corroded. There could also be an issue with the wires touching that lead into the trailer connectors.

If you have access to a different trailer or tow vehicle you could save yourself some time and easily determine which side the issue is on, truck or trailer.

expert reply by: Conner L