Everyones favourite subject! Trailer lights

[Mauro]

I had a similar issue with my trailer. It turned out to be a blown fuse in the truck.....some of my trailer lights worked, others didn’t ( clearance lights etc.) don’t ask me why, but the dealer checked my truck fuses and one was blown. (2014 Ford F-150)

same here
i checked the fuse panel on my truck and there was a blown fuse.

[blasted_saber]

Update - It was a wiring harness in the vehicle.

Nothing is simple or cheap in new vehicles.

[faderinse]

Put a good clean grind to the trailer frame, re-attach the ground wire and try again. If you have a multimeter you can check the ground on the vehicle side BRANCH SWIVEL-NICKEL PLATED - BR-SWIVELNP-XX. I've had trouble with this before and the trailer lights would work after a few bounces down the road it would ground through the hitch but the vehicle ground through the connector was corroded where bolted to the frame