F350 Trailer wiring fault when towing my XLR

I know this might not be your problem, but if you haven't checked it out its worth a look. With one of our many trailers, the factory attached plug was the problem. As soon as we hit a big bump or turn just right, the truck would say trailer disconnected. It would happen so fast that the lights would just flicker for a second. We buy one like this and have used it on multiple trailers. https://www.etrailer.com/Wiring/Hopkins/HM48510.html

I hope you can trace the wires if that is your problem. I can't trace mine very far. Good luck.