Reese Brakeman 83501 Only Sends Power to Trailer Brakes When Using Manual Over Ride

Expert Reply:

Assuming the rest of the brake controller is wired properly, the blue brake switch wire should be sufficient to tell the brake controller that the brakes have been pressed. My thinking is that you need to adjust the power output on the brake controller. If the output control is set too low, you may not get sufficient braking power until you use the manual over-ride switch. If the power setting is at an appropriate level, there may be a wiring problem.

Double check your ground. Make sure it has good contact with the metal surface. Paint can insulate the connection. The red wire on the brake controller should be connected to whatever wire goes hot when the brake pedal is pressed, in this case the blue wire coming off the brake pedal switch with 3 to 4 volts is at the lower thresh hold of power needed for activating the brake controller.

You might want to check to see if there is another switch for the brake pedal. Many vehicles now have multiple brake pedal switches. If you do not find a wire with more than 4 volts when the brake pedal is pressed, the next step would be to talk to someone at the Pontiac dealer who may be able to tell you which wire you need to splice into. There are normally 3 options other than the brake pedal switch, but they are much harder to locate.

The first option is at the BCM or body control module, the next option is splicing into the CHMSL or center high mounted stop light circuit, and finally some vehicles with cruise control have a wire that can be located and spliced into. A knowledgeable service technician should be contacted for location and directions related to using any of these alternate locations.

expert reply by: Patrick B