Are Trailer Brake Magnet Wires Polarity Sensitive?

Updated 09/28/2026 | Published 09/23/2026

Question:

Does polarity make any difference when installing replacement trailer brake magnets? I ask this question because both wires are the same color on my existing magnets.

asked by: Aaron G

Expert Reply:

Hey Aaron, this is a great question but trailer brake magnet wiring is not polarity sensitive. So either wire can be used for power as long as the other is grounded. This is true for the Lippert magnet kit part # LC47ZP that you referenced which has two green wires.

expert reply by: Jameson C

Dave P.

9/25/2026

I recently installed this magnet. There is a spring under the magnet, I found that the original spring had a locating pin, the replacement that came with the magnet did not fit as well, so I re-used the original spring. Take a picture of the old wire routing and clip orientation and position so you can replicate it with the new wires. My experience has been that trailers with electric brakes use 2-conductor wire and run the ground all the way to the common grounding point on the tongue or in the junction box. In this instance, a white wire in the 2-conductor is ground, but actual polarity at the magnet wires does not matter.