Troubleshooting Constant 12V Power From Brake Controllers on a 2001 Dodge Ram 3500

Updated 02/13/2023 | Published 02/11/2023

Question:

I have a dodge 2001 ram 3500 which factory trailer brake wiring. I am getting 12 volts constantly to trailer brake plug. I have plugged in two different brake controllers to rule out a bad controller and i still have 12 volts. I have unplugged controller and tested the trailer brake wire circuit with a olm meter to see if factory wiring is shorting out with any other factory wiring to trailer brake wires. All indicate ok. What else cold casue me to get voltage when controller is plugged in?

asked by: Mark

Expert Reply:

The only thing I can think of is if the OEM plug for the brake controller is bad and allowing 12V power meant to power your brake controller to jump over to the output power wire for the brake controller to your trailer brakes.

If you test the blue output wire when your controller is connected then you should see that constant 12V power. At this point your best bet is to either replace the pigtail, like part # 3020-P for a Tekonsha brake controller, or cut off the OEM plug and hardwire everything together if you're able to determine that it's the OEM plug and not the adapter wiring.

It's probably not what you wanted to hear but that's the only way I can see the issues you're dealing with actually being a problem. Hopefully this helps you out!

expert reply by: Jon G