Help trailer brakes went out (UPDATE)

Ok. Here is an update. Turns out that it was a bad ground in the junction box on the pinbox that the incompetent boobs at Manteca Trailer installed to fix another issue in the wiring. They didn't crimp one end of the butt connector for the main ground. Re did all the ground wires and voila, brakes now work fine. Every time my trailer was in that shop for warranty work they messed up something else, EVERY TIME!!!! Now that the trailer is out of warranty they will never see this trailer again!

Thanks to all for your suggestions and input, it is much appreciated.

Steve