Trailer Brake or Truck Problem?

thomasmnile wrote:
Well, my issue isn't with the 110v power, but I bought a good test light today and will begin the detective work starting with the truck, which I just got back from the dealer for the Takata 'airbags of death' recall repair. Both driver and passenger bags replaced.

When did the 110volt side if your system come up??
Everything we have been talking about re your truck and trailer, especially brakes, is 12 volts.
I still say you have a chafed wire that is creating an intermittent short in your brake circuit.