How to Test to Determine if Older Brake Controller is Bad

Published 04/17/2019

Products Featured in This Question

Tekonsha Prodigy P3 Trailer Brake Controller - 1 to 4 Axles - Proportional

(6643)

$169.94

Hook Probe Circuit Tester

(60)

$12.27

Question:

hi i have a 10 year old Tekonsha Brake controller and it just started to act erractic. the Green LED light will barley go red even with the Gain all the way up and brakes applied and the slide bar wont work either. do the electric controllers go bad over time?

asked by: Jeffrey H

Expert Reply:

Brake controllers don't typically have an expiration date but the longer you use them the more chance you run of there being a short wiring issue that can damage the controller internally. I can help you test the controller though to find where the issue is.

Testing the brake controller is fairly easy. Sever the blue brake output wire near the brake controller leaving enough room to reconnect it and then apply the manual slide. Using a circuit tester like the Quickee Tester, part # PTW2993, you should get output to the controller side of the wire you severed. If the manual slide activates the trailer brake output wire properly, try the brake pedal. If the brake pedal activates the brake output properly also then the problem is farther back either in the vehicle wiring or on the trailer.

If either the brake pedal or the manual slide are not functioning properly you will need to test the wires going into the brake controller. Make sure you have power entering the brake controller on the black wire. On the red wire you will only want power when the brake pedal is pressed.

If there is power on the red wire before the brake pedal is pressed you have connected the red wire from the brake controller to the wrong circuit. You would then need to find the brake switch wire that has power ONLY when the brake pedal is activated.

If these connections check out and the brake controller is properly grounded then there is possibly a problem inside the brake controller.

I am including a link to a video that will show you how to test the wiring on a brake controller.

The brake controller I recommend as a replacement is the Prodigy P3 part # 90195 because this brake controller senses the amount of braking your tow vehicle is applying and puts a proportional amount of braking on the trailer's brakes. It also has a display that uses full words instead of codes that would have to be deciphered. It's our best selling brake controller because of how well it works, how reliable it is, and how easy it is to use.