I have a 20' enclosed trailer with brakes on all 4 wheels. This trailer is about 18 months old. Last week the brakes quite working, the brake controler in the truck now does not light up. I checked the wires and I am getting power to all four wheels, so I unhooked the trailer to check the ground and all the lights worked. All my other trailers work fine so it should not be my controller. Can the magnets give out and cause this problem?