Troubleshooting Trailer Brake Magnets that Have Voltage to Them But Arent Activating

Updated 04/24/2017 | Published 04/23/2017

Question:

we cut and separated each wheel magnet wire at backing plate. with good 12.9 volt battery directly connected to magnet, brakes do not engage on any of the 4 wheels. do not get a ohm or amp reading on any of the magnets when hooked to battery for testing. i have no way of pulling rims but it does not seem likely that all 4 magnets went bad at the same time. really need help thanks

asked by: Barry J

Expert Reply:

It has to be the ground then of the brake magnets. If they are all getting voltage and not applying the problem is the grounds. Make sure the magnets are connected to a clean portion of the trailer frame or you can run ground wires from each magnet back to the main ground of the trailer wiring harness. When the magnets are activating you should hear them click as they grab the drum and you'll also hear a low hum too.

expert reply by: Jameson C