Brakes Not Receiving Power when 2013 Ram Wiring Harness Connected to 7-Way

Question:

I have a 2013 ram 3500.....at my plug on the truck I dont have any more than 1 volt to the constant 12v power but my running lights work when the trailer is plugged in the brakes do not. Unplug the truck harness from the receptacle on the bumper and theres 12v all the way through. As soon as I plug it back into the receptacle the power is gone. Just bought a brand new receptacle and its the exact same problem. All the fuses are good. Im stumped at this point.

asked by: Joel S

Expert Reply:

It sounds like the wiring harness in your truck is receiving 12 volts of power when unhooked from the 7-way connector at the back of your vehicle, but is loosing this power when connected.

It is possible that there is a bent pin on the vehicle side harness. If that is the case, it will probably test fine when you are checking the pins with it unhooked from the receptacle, but once it is hooked in, the bent pin is not be able to make full contact with the receptacle side. I recommend checking the vehicle harness to see if there are any bent pins. This can usually be remedied by just manually straightening them. If you find you need to replace the harness completely, you will need to visit your local Ram dealer for the necessary part.

The running lights are still working because the 12 volt power circuit you are losing is not used to give power to the trailer's light functions.

Lastly, make sure you are correctly testing the brake controller. Instead of pressing on the brake pedal in your vehicle to test the brake function, use the manual override switch on your brake controller to send power in order to isolate any potential problems to within your wiring setup.

expert reply by: Chris R