What Would Cause Trailer Running Lights to Be On All the Time

Published 10/26/2021

Question:

I have a 2017 Ford F 250 Lariat every time I plug my living quarter horse trailer in I have brake, turn signal lights however the running lights stay on all the time even when the truck is turned off draining the battery what can I do to fix this problem or what is the problem?

asked by: Tina C

Expert Reply:

What you have is a short between the 12 volt accessory circuit which is in the 1:00 position of your 7-way and the running light circuit which is in the 11:00 position and basically the 12 volt circuit is powering the running lights to be on all the time. So what you'd want to do is go over the wiring of the 7-way and fix any obvious signs of a short like exposed wire.

expert reply by: Jameson C