slard

I have an F150 2014 Ecoboost with the towing package. When we took delivery of our travel trailer in the fall the backside of the 7 pin was loose. The camper place zip tied the harness down and we were able to get the TT home. Took the truck to the dealer to fix it.

Hitched the TT for the first time since the fix and had no lights/brakes/dash says trailer disconnected. Wiggling everything I could touch did nothing. Drove very slowly and when the truck angled from the TT to the left, the lights went on. Straightened and they went out. Connected the TT to a Chrysler mini van's 7 pin and immediately got lights. Hooked a jumper cable to a bolt on the TT and a bolt on the truck frame and got lights. So there is a ground issue, likely a temporary open.

Two days at the dealer and they can't find anything wrong with the truck. I'm sure their test circuits aren't creating enough of a draw. I connected a different 2014 F150 to the TT and got no lights. Then tried a 2014 F250 and got lights.

Anyone else run into such an issue? Why should two F150s not work? And how do I get the dealer to pull their heads out and actually investigate the harness and ground wire?

brulaz

Could just be coincidence, and you have an erratic problem with the ground.
Problems like that are really hard to figure.

Did the dealer replace the whole 7pin plug and cable?
That might be the next step.

Or perhaps the trailer's plug and cable, unless it always works on other trucks.