Troubleshooting Brake Controller Only Sending 12V Power with Manual Override

Question:

I have been chasing my tail for weeks tried new brake controller and had someone hook to my trailer. So the issue is with my truck. I get no power to the trailer when brakes are applied. I do get power with the manual at times. I did check the voltage no voltage for brakes being applied at controller or at 7 pin. I did get 12 volts for manual brakes on both ends. Not sure where to start any help would be appreciated. I also checked all fuses that apply

asked by: Scott M

Expert Reply:

From what you stated it sounds like you have a proportional brake controller like the Tekonsha Primus IQ # TK90160. This kind of operation is normal for a proportional controller because they have an internal inertia sensor that helps to determine how much power needs to be sent back when you are coming to a stop. If you are testing all of this while sitting still then the inertia sensor can tell that the vehicle/trailer isn't moving and so no power is needed for the brakes. The manual override, on the other hand, sends back power no matter what.

If you have a different controller or you aren't getting brake power with the pedal action while moving please let me know and I can help you troubleshoot further.

expert reply by: Jon G