[norcal retiree]

So far, I've found the trailer brake fuse on the truck blown. Replaced fuse, still not recognizing trailer brakes. Thought I had found the problem.
All running, t/s and brake lights work fine. There was some rust/corrosion in the 7-pin connecter, which I cleaned. I also visually inspected the cable and wire connections. Next step is to hook up trailer without the nylon pad.
If no change, then I guess my next move is to start pulling wheels and inspecting the magnets and wiring.