Testing Trailer Magnets On A Trailer With 12" Electric Drum Brakes

Question:

how do you know if the magnet is working, i had 3.5 volts on my gauge an the magnet hardly had any stick to a screwdriver head, it has a faint hum, but the pads look to have not touched the drum on the last 450 mile trip, everything is moving ok, even the star, thanks

asked by: Steve T

Expert Reply:

I have linked an article below on testing brake magnets for you to reference.

You will need a Multimeter # PT89ZR to test the magnets in the Dexter Electric Trailer Brake Kit # 23-434-435.

First you will begin by testing the output coming from the vehicle. Each magnet should see 3.2-4.0 amps of power between 12-13 volts with the brake controller set to max. This test can also be performed with a 12v battery to determine if the problem is with the brake controller or wiring and not the magnets.

You can do an ohm test on the individual magnet to ensure it has the proper resistance. This should be between 3.0-3.8 Ohms when connected to both wires on the magnet.

expert reply by: Bud M