Brake Controller Installed on 2015 Ram 2500 Only Showing 1 Volt of Output When Tested

Updated 07/29/2021 | Published 07/28/2021

Products Featured in This Question

Tekonsha Custom Wiring Adapter for Trailer Brake Controllers - Dual Plug In

(262)

$18.81

7- and 4-Pole Trailer Connector Socket w/ Mounting Bracket - Vehicle End

(2589)

$42.67

Question:

Hello, I have a 2015 Ram 2500. I found my 7prong wiring harness “trailer break” was only receiving 1 volt when actuated. I changed out every fuse I could find, including f11. I also replaced the 4/7 prong harness located on the rear bumper. All of the other prongs are working appropriately. Do you have any ideas before I try replacing the factory female 7 plug? Thanks

asked by: Josh

Expert Reply:

What's going on when you're testing the controller? Which controller do you have?

If you have a proportional brake controller, you're only going to get a tiny bit of voltage on the output circuit with the brake pedal (which tells the controller whether a trailer is connected or not), because a proportional controller will only output voltage with the pedal when the vehicle is in motion. If you're testing using the manual brake switch on the controller, you should be getting voltage commensurate with how high the gain on the controller is turned up.

If you do not, you'll want to sever the blue wire exiting the rear of the controller (leave enough slack so you can easily reconnect it) and test the wire with a # 40376 circuit tester while activating the manual brake switch. If you get power, then there's a break somewhere between the controller and the 7-way. If you don't get signal, then the controller is faulty and should be replaced.

If you have a time delayed controller, you're supposed to see voltage on the 5:00 pin in the 7-way with both the manual switch and the brake pedal.

I'll link to an article that shows additional troubleshooting steps.

expert reply by: Mike L