Troubleshooting Brake Controller Still Showing SC Error After Replacing Vehicle and Trailer Wiring

Question:

Hello I have racked my brain trying to find the issue which is causing my brake controller to display “SC”. Occasionally the brakes will work for a short time while driving but then after holding the brake pedal in till the voltage reaches its setting the code SC will flash. Sometimes while sitting still the brakes work fine and the code won’t come on however seems like the issues start when the trailer and truck is moving. I have checked all my wiring even replaced most of it and checked the ground the trailer to the hitch is connected to by sanding down to bare metal. I cannot come up with any possible solution. The signal reaches to the back of the trailer with test light while the brake pedal is pushed in but again when my truck is moving it will mess up work for a short time then quit. Any ideas?

asked by: Josh S

Expert Reply:

Without knowing what type of brake controller you've got I can generally say that the SC error, as you've seen, comes on when a short is present on the brake output circuit. If you've replaced all of the wiring along the brake output circuit then it's unlikely the wiring has been damaged again, so the other thing to take a look at is the brake magnets themselves-it's possible the short is there. Check the wiring to the brake magnets themselves and test the magnets for proper functioning.

If you don't already have a multimeter to run these tests you'll want something like the Digital Multimeter with 42" Long Test Leads - LED Display # PT89ZR. I've also linked a helpful article we did on testing brake magnets to this answer. If you can let me know the year, make and model of the vehicle and the type of controller you're installing I might be able to provide more specific troubleshooting steps.

expert reply by: Erik B