Dexter axle Brakes

#1 reason electric trailers brakes don't work is electrical integrity. Scotch Locks should be illegal on certified DOT approved manufactured trailers. All mine are re-wired with a ground wire that is connected directly back to the plug ground connection which eliminates the assumed frame grounding through the hitch connection. #2 the surface that the magnet rides against needs to be clean and that's why it takes a while for trailers that have not been moved for a while to have poor brakes temporarily. Adjustment just as important as everything else which includes shoe to drum diameter match. A proper butt/crimp connected wire with "double wall" shrink tube will last as well as a soldered joint and allow more flex in the wire and joint. Re-wired many horse trailers with serious gravel rash and lasted years before needing attention.