I've got a 97 Ram 2500 4x4 with the 5.9 Cummins and I'm trying to get the trailer brakes working. I have the harness that plugs in near the park brake installed. When I checked to see if the controller was working I found the indicator light on the controller was on. I checked the brake light switch and it is ok. The truck brake lights are not on. I checked the wires going to the controller and found the red wire is hot (12 volt) all of the time. The black wire no power and the white wire is ground. The blue wire is gowing to the 7 pin plug. I checked the pins on the plug and everything checked out good. I thought that the red wire was the signal from the brake light switch and the black was constant hot. I didn't find the signal from the brake light switch. What am I missing??
Thanks
Oldsarge29

The blue wire goes from the controller to the 7 pin plug at the rear. For some reason I'm not getting a signal from the brake light switch. The brake lights on the truck work right and everything else now seems to be right.