Should a Trailer Brake Controller Be Sending Back Power All the Time to the 7-Way Connector

Question:

On a 7 pin connector, is the pin for the brake controller supposed to have power on it? Only when braking? All the time? I have an older Tekonsha controller. It only lights up when the trailer harness is connected.

asked by: Chuck H

Expert Reply:

There should only be power on the brake output circuit when the controller is being used. But it can send small amounts of power back from time to time to check for a trailer. On some brake controllers, especially older models, the indicator light will only come on if a trailer is connected.

To test a brake controller to make sure it is sending power back when it is supposed to, you will need a circuit tester, # 40376, if you do not already have one. Sever the blue wire a few inches back from the controller. Use the tester to test the end coming from the brake controller. It should only show power when you apply the manual override. If it shows power at any other time or constant power then there is something wrong inside the controller and it will need to be replaced.

If it checks out fine then make sure to reconnect the blue wire. I have included a link to an FAQ article on more information on ways to troubleshoot a brake controller.

expert reply by: Michael H