Troubleshooting Constant Power Being Sent to the Trailer Brakes from Brake Controller  

Question:

Expert Reply:

If you have a brake controller, like the Tekonsha Prodigy P3 # 90195, installed in your tow vehicle then you will get some sort of power reading on the brake controller pin of your 7-Way ( 5 o'clock pin in the attached picture). This is the brake controller sensing if the trailer has been connected and is normal.

However, if you are getting a full 12V at that pin without pressing the brake pedal in your tow vehicle then something is definitely wrong. Start off by checking the 7-Way on your tow vehicle to make sure that there is no corrosion or debris that would be causing problems. Next you will want to use a Circuit Tester # PTW2992 to see if there is full power on the 5 o'clock pin without the brake pedal being applied.

If there is, then you will want to check the Red wire on the brake controller and make sure that it is connected to the COLD side of the Stop Light Switch (only gets hot when brake pedal is pressed). If it is connected to the HOT side then it will be sending a constant signal.

If your brake controller was hardwired in then it is very possible that the 12V power wire that is meant to power the controller is actually connected to the wire that is supposed to send power to the brakes.

If you are still having troubles after this troubleshooting then let me know which specific brake controller you have and what the year/make/model is of the vehicle you are installing it on and I can see if there are any specifics that I can give you for the install. I have also attached some helpful articles that you can reference for troubleshooting.

expert reply by: Jon G

0

click to enlarge