Troubleshooting Trailer Taillights that Stay On When Not Connected to Battery or Vehicle

Updated 06/18/2019 | Published 06/17/2019

Question:

We have a 2007 cougar 311efs 5th wheel.The problem is the back running lights and markers stay on all the time.There is no battery in the rv and it is not hooked up to the truck.This was the first weekend that they have been on.None of the switches on the rv would turn them off.We did have a squirrel in the camper this past winter,but everything was working properly for the last month and there was no new sings of our little freind.Any thoughts would be appreciated.

asked by: Rob

Helpful Expert Reply:

So the trailer is not connected to your tow vehicle and there isn't a battery on the trailer but somehow the lights are staying on all the time? Does the trailer have a breakaway battery at least? Most likely it does and that would be about the only thing that could power the taillights of the trailer. Best option would be to go over the wiring of the battery and see if there's anything obvious that would short it out to the taillights like cut or exposed wire caused by the squirrel.

expert reply by: Jameson C