Electric Trailer Brakes That Stopped Working Moving Forward But Work in Reverse

Question:

What would cause the brakes to quit working on my tandem axle trailer? We got this trailer used so dont know much about it. It is an open car trailer we use to haul a race car. The brakes were working just fine when we went to the race track last night. When we left to come home the brakes were not working. They only work when backing up. Would being out of adjustment cause this? It is a tandem axle trailer but the rear axle were the only brakes that worked and worked just fine until last night. Could this be caused by a bad connector at the trailer? As I tried to say at the beginning we know very little about this trailer. Any help you could give would really help. Thanks.

asked by: Gene

Expert Reply:

When there is bizarre trailer brake behavior the first place to check is the trailer connectors for corrosion. Check out the trailer connector on your tow vehicle for corrosion and clean as necessary.

Electric trailer brakes aren't really designed to work well in reverse. You should feel a slight drag, but nothing like the braking power the assemblies would have while traveling forward.

They could be out of adjustment, but most likely they wouldn't just go from working normally to just nothing at all if the adjustment was off.

I would first start by testing the brake output circuit on your tow vehicle just to verify that the problem is on your tow vehicle. To do this you will want to use a circuit tester like part # 3808 to test the brake output pin of the connector while a buddy slides the manual override of your controller. You should see voltage there.

Now since you said only certain brake axles were working that makes me think maybe you have some wiring issues that need to be sorted out. It could be that there is some loose wiring on your trailer and the movement of loading and unloading your race car caused the loose wire to lose contact or caused some exposed wire to touch the frame of your trailer and shorted it out.

You will also want to check the conditions of grounds on all of the brake assemblies on your trailer. They all should be connected to a clean metal surface.

I attached an FAQ on trailer wiring for you to check out also.

expert reply by: Jameson C