NC Code on Tekonsha Prodigy Brake Controller After Installing 2nd 7-Way Trailer Connector

Updated 09/25/2024 | Published 01/01/2016

Question:

I am getting a nc code on my brake controller without the trailer hooked up When i put my foot on the brake pedal it goes out this started when I hooked up a 2nd 7wire plug I have took the second plug off but am still getting the code any thoughts on the problem.

asked by: Rufus F

Expert Reply:

The nc code on the Tekonsha Prodigy brake controller indicates that no trailer is connected. When you step on the brake pedal though it should still say that the trailer is not connected.

It is possible that there is a short being caused by a dirty or corroded connector. Make sure that the connector is clean and free of corrosion inside where the wires attach and outside on the pins. Also check where you Teed into the harness to add the second 7-Way and clean and repair wires/connections as needed.

There are some tests you can do to determine if the brake controller is the problem. In the truck cab you will need to sever the blue wire several inches from the back of the controller. Then use a circuit tester such as # PTW2993 to test the end of the blue wire coming out of the controller. It should only have power when you apply the manual override. If it shows power at idle, then there is something wrong with the controller and it will need to be replaced.

If it tests fine then reconnect the blue wire. Then move on to the truck side trailer connector. You can test the brake output pin and it should only show power with the manual override. If it shows power any other time then there is a short somewhere between the connector and the brake controller you will need to track down.

If the truck side checks out fine, and the problem happens with the trailer connected, then it could be the wiring to the brake magnets or the magnets themselves. Inspect the power wires to the magnets and look for pinched, frayed, or damaged wires and fix as needed. Make sure the ground wires are attached to clean and corrosion free bare metal surfaces.

You can visually inspect the magnets and if you can see the copper windings coming through the magnets will need to be replaced. To further test the magnets, you can follow the help article I have linked. I have also included some help articles on testing and troubleshooting brake controllers for you.

expert reply by: Michael H

Jeff N.

9/25/2024

So if I understand correctly, if NC is displayed when there is no trailer connected, the controller is functioning normally when using the vehicle brakes to stop or slow down?