I Rewired My Trailer and the Brakes Do Not Work

Published 09/03/2014

Products Featured in This Question

Replacement Magnet Kit for 10" Electric Trailer Brake Assemblies - 3,500 lbs

(121)

$29.48

Hook Probe Circuit Tester

(65)

$12.94

Question:

I have completely rewired my trailer with copper wire its a 72 kit companion every time I hook up my 2011 dodge truck it tell me my trailer brakes need attention and they only work once in a while my ground is good and the wireing is 10 gage to the breaks I think its my truck can you give me a pointer or two.

asked by: Val

Expert Reply:

Poor or intermittent brake performance can be a result of a few different issues. Poor ground connections, corrosion build up and shorts are the most common culprits. If you are certain that all of your grounds are good, then I would look at the trailer connectors for white or green corrosion build up and clean or replace as necessary.

I would also look at the electric brake power wire for any pinched, frayed, or damaged sections that could be causing a short. We had a similar issue after installing new wires and brakes on a trailer and found that we pinched a wire between the brake assembly and the mounting flange causing the brakes to function sporadically.

If all of these check out fine, then I would grab a circuit tester like part # 40376 to test the output power of the brake controller. First, set the power to the max on your brake controller. Have a helper hold the manual override lever on the brake controller while you test the 5 o'clock pin in your trailer connector (see photo). You should have full power with the brake controller. If not, go back to the brake controller and cut the blue wire about 6 inches back and test it again. If you have full power at the brake controller, but not at the trailer connector, then there is an issue with that wire on the truck. I would recommend running a new wire back to the trailer connector assuming the trailer connector itself is not the problem. If the trailer connector is the problem, then it should be replaced.

I have attached a few help articles on trailer wiring and brake controllers for you to check out. If you cannot find the problem or a solution after following these steps, let me know.

expert reply by: John H