Overload Error Code Troubleshooting on a P3 Brake Controller

Question:

I have a 01 Sierra 2500hd. I just received my p3 today and installed. It seems to work but when I apply the brake fairly stiff and quick it reads overload, no brakes?

asked by: Nate

Expert Reply:

The OVERLOAD error message you are experiencing is caused by a high current draw from the brake circuit. In other words, there is a short somewhere in your brake output circuit. Typically the problem can be found at the trailer connector, on the brake output circuit on the trailer, or at the wiring connection at the brake magnets.

Start by examining the trailer connector on the trailer and the vehicle. Make sure that there is no damage or corrosion and that the wiring connections are secure. If you can see any green corrosion on the sockets or pins on the connector, there is a possibility that the corrosion has spread to the interior connections and is causing a short. Next, trace the brake output circuit from the trailer connector on the trailer (usually the blue wire) back to the brake magnets. Look for any points where the wire is pinched, or where the wire insulation has been rubbed off or is cracked. Any missing wire insulation can cause the wire to short to the trailer frame. Finally, check the point where the brake output wire connects to the brake magnets. Make sure these connections are secure, and that one lead from each brake magnet is attached to the output circuit, and the other is grounded to the trailer frame.

I have attached a link to an FAQ page that has many troubleshooting techniques for you to check out too.

expert reply by: Jameson C