Troubleshooting Trailer Wiring Where Turn Signal Lights Up All Trailer Lights

Updated 04/30/2018 | Published 04/28/2018

Question:

Hi guys I have a strange issue with my trailer lights, I have a 2015 Ford f150 and two an open car trailer. with my vehicle lights turned off, I have normal operation of turn signals on my trailer but when I apply the brakes it seems the dimmer taillight filament lights up, when I turn the lights on on my vehicle I get the brighter brake lamp filamnet lighting up on the trailer lights no matter if the brake is applied or not and the turn signals do not work on the trailer. Any input on what you might think this is would be appreciated. Thank you.

asked by: Michael N

Helpful Expert Reply:

Either on your trailer's wiring or on your vehicle trailer wiring you have the stop/turn signal and running lights circuits swapped. Since the truck is newer I'd imagine the problem is more than likely on the trailer side. But all you'll need to do is swap the two wires of the running lights and which ever stop/turn circuit you have wired backwards.

expert reply by: Jameson C