Troubleshooting Constant Power to Brakes With Prodigy P3

Question:

I hooked it up everything works but it is putting 2.4 volts to trailer without stepping on brakes. If I unhook power the trailer rolls freely otherwise it holds on slight incline.

asked by: Tom W

Expert Reply:

It sounds like you're getting constant low power to the brakes on your trailer with your Prodigy P3 # 90195. I would start by testing the brake output wire at the brake controller itself using a circuit tester like the # PTW2993. If you have that voltage reading at the brake controller itself, it is a problem with the brake controller and you will need to replace it. More than likely this is the issue since it sounds like you pulled power to the brake controller itself and that stopped the problem.

If not, then I would move to the back of the vehicle and test the brake output at the 7-way. I would also check the 7-way for debris or corrosion that could allow power from the 12V pin to travel over. If you have power at the 7-way then it is probably a short in the wire. You can check for a short and repair as needed, or run a new wire using the # 10-1-1.

If it is not present at the vehicle side 7-way then there is an issue on your trailer. I would again check for a short in the wiring and where the wires are attached to your brakes.

expert reply by: Robin H