Troubleshooting 2006 Dodge Ram 3500 Brake Controller Losing Voltage at Truck Side 7-Way

Question:

i have an 2006 ram 350. I have 12 volts on the out put side blue wire but only 4 volts and the 7 way pin connector on the truck

asked by: Bob W

Expert Reply:

If the brake controller on your 2006 Dodge Ram 3500 is putting out 12V right behind it, like you would find on the blue wire of the Prodigy P2 # 90885, then you have a damage wire somewhere between the controller and the 7-Way connector at the rear of your pickup.

Before tracing the output wire from your controller to the 7-Way I do recommend making sure that your 7-Way truck connector is in good shape and that you are testing the output wire for the brake controller as aftermarket controllers do have a wire that runs directly to the battery for constant 12V power. The common wire colors on aftermarket brake controllers are as follows:

Blue - 7-Way Output to Trailer
Black - 12V Power
White - Ground
Red - COLD Side of Stop Light Switch (only gets hot when brake pedal is pressed)

This isn't a hard and fast rule though so if you have different colors don't worry about it. Just make sure that the blue wire you are testing doesn't have power output until you apply the brakes or manual override on your controller.

If you inspect the wiring and can't find anything wrong with the 7-Way connector or your wiring then I recommend routing new 10 gauge wire # 10-1-1 from your brake controller output to the 5 o'clock pin on your 7-Way.