I recently brought a 2002 Dodge Ram 2002 cummins truck, mainly to pull my Super M tractor. The problem is I have a fifth wheel with electric brakes and they are not working. I have a brake booster in the cab and i'm getting nothing at the plug. I have brake lights, turn signals and hazards light but no running lights and power brakes on the trailer. I took a volt meter to the plug and I have nothing. I check up front and I had a blown 40 amp fuse. I changed the fuse and still know electric brakes on the trailer. Please help I have to get this fixed by next week for a tractor pull.

 

Did the brake box come with the truck, or did you get one after the truck purchase and plug it in your self? You may be best off, for the sake of time, to buy a new box and harness. Then follow the install instructions and run new wires to the existing plug (after you remove the old wires). It could be a bad controller or wire effecting your system.

 

Moved to the diesel section, bump to the top.

 

you may want to do a continuity check on the wireing harness to make sure you dont have a hot ground. I had a similar issue on a work truck in a previus life, come to find out the trailer was wireed wrong.