Using PTW2993 Circuit Tester To Check Brake Controller Output

Question:

Which is the appropriate pin?

asked by: Deana B

Expert Reply:

I'm not sure what you're needing to test, but I can see that you checked out a question about testing trailer brakes. If that's the case, I'd be happy to help.

Most trailers with electric brakes use a 7-way trailer connector. If you look at the 7-way trailer connector on the vehicle, the pin to the lower right (which would be in the 5:00 position if you compared the pins to the face of a clock) carries the output circuit for trailer brakes.

The brake controller has a manual brake switch on it that will apply the trailer brakes independently from the vehicle brakes. Have a helper activate the manual brake switch on the controller as you test the pin. If the controller is functional and everything's installed correctly, you should see power on that pin. Also, if you have a time-delayed type controller, you will also see power on that pin with the brake pedal. However, if you have a proportional controller, you won't get output to the pin with the brake pedal unless the vehicle is in motion. You will however get signal with the controller's manual brake switch.

If this isn't what you were needing, please reply and let me know what you're needing to test and I'd be happy to help.

I've also linked to some articles about brake controllers and trailer wiring that you might find helpful.

expert reply by: Mike L