How Much Voltage Should be On the Red P3 Trailer Brake Controller Wire

Updated 01/23/2014 | Published 01/22/2014

Question:

I am looking at the Prodigy P3 brake controller, but I need to know the minimum voltage that is required on the red wire for the unit to activate? Thank you for your help.

asked by: Brandon

Expert Reply:

The red wire is the input wire telling the brake controller that you have stepped on the brake pedal. This should be a 12 volt wire on the cold side of the brake switch if hardwiring the controller. Some vehicles, like the 2013 Chevy Silverado, already have a tow package wire bundle under the dash, to the left of the steering column, held together with a white tag. The white tag also should have the functions of each wire on it.

The brake controller wiring is black for 12 volt power to the controller, white for ground, red for input to the controller, and blue for output to the trailer brakes.

Some vehicles, again like the 2013 Chevy Silverado, may require additional connections under the hood to make everything fully functional. I have included a link to a how-to article that explains these connections.

expert reply by: Michael H