Trailer Running Lights Blow Fuse on Tow Vehicle When Connected

Updated 04/07/2015 | Published 04/05/2015

Question:

My trailer running lights dont work and everytime I replace the fuse, it pops whenever I turn my lights on.

asked by: Matthew T

Expert Reply:

What you are describing is a short circuit. The short could be anywhere from the vehicle side connector back to the trailer tail lights. First, disconnect the trailer from the tow vehicle. Next make sure that the vehicle side connector is clean and free of corrosion inside and out. I have also included a link to a help article explaining wiring troubleshooting.

On the trailer side, check its connector and make sure it is clean and free of corrosion inside and out. Next you will need to inspect the trailer wiring from the front to the back. Look for any pinched, frayed, or otherwise damaged wires and fix as needed.

Also inspect the light and make sure the wiring going into them is in good shape. If the trailer has a lot of running lights then it is also possible that the combined amperage draw is too much for the tow vehicle wiring. You could test that by disconnecting some of the lights and then plug in the trailer and see if the still connected lights will work.

expert reply by: Michael H