Both Left Side Brakes Work on Trailer but No Right Side Brakes

Published 08/10/2018

Question:

2014 25 foot Airstream International. Nancy and I are going through the entire trailer. In the process, it was discovered that the Right Side Brakes, passenger side to the vehicle, do not work. No hum. Not even a slight change in braking. Unlike the opposite side that work immediately by braking with the Tow Vehicle brake, or the manual braking from 0 to 10. Turn signals and side lights all work fine. The Left Side work, lock up after manually spinning them. Pulling the Break-Away-Switch, the left side brakes lock up. So Power is getting to the left side from the F350 Trailer Brake System, but none to the right side. The wiring appears intact from the the covered cable going into the bottom of the trailers aluminum skin. The wires appear fine into the two brake assemblies. My first assumption is that there is, of course, no 12v power to the Right side. But why? Is it a ground, somewhere? Is there a fuse, somewhere? Are the brake magnets at fault? I never have taken each wheel off the ground in the four years owning this trailer to test each individual wheel braking. I discovered this problem yesterday going through a testing of everything in the trailer. Could it be two faulty brake magnets and just a coincidence the same side both failed? Since I cannot say these have ever worked, could there be a wiring issue? As I have said in the past... I am electrically challenged. Once some things can be eliminated by testing, the true source of my problem may be solved. Has anyone else had one SIDE or the OTHER have no issue, but the other side has no power going to both side brakes? _

asked by: Ray

Helpful Expert Reply:

The issue you described is more than likely attributed to a wiring issue. The issue could be either a short in the brake output wire or the ground. The brake output wire at some point will break off from the main lead and branch off to each assembly. You will need to trace the brake output wire back from the trailer connector until the point it branches into the right side braking assemblies. If there is any wire loom or jacket encasing the wires you will need to remove it so you can get a clear picture of the condition of the wire. If you are absolutely certain there is no breaks or shorts in the brake output wire then you will then want to move onto the ground for each assembly. It might be better to reattach the grounds after sanding down the mounting surface.

The above process should fix your problem but if not you will want to run a new brake output wire from the battery to each assembly to make sure the magnets are getting power. If still no brakes then the magnets are subsequently bad on both assemblies and will need to be replaced accordingly but odds are it is a wiring issue since both are out on the same side.

expert reply by: Conner L