hi all i have had my 04 longbox for years now and it always had a brake controller in it,i recently bought a 5thwheel camper and when i hooked it up the controller doesnt do anything,it lights up when i apply the brake but nothing on the trailer end of things,i had my dad also haul the 5thwheel with his cummins and the brakes worked fine so i know its my truck not the trailer,where would be a good place to start looking,i believe theres a factory plug into the brake controller,am i correct?what voltage signal shouud i see at the conector,i will use the conector with a multi meter,thanx for any info or tips,

 

There are four wires on the back of controller.
-Blue is brake and will have between +1v and +12v; depending on your settings; when the brakes are applied
-Black is the power +12v which is present when key is on
-Red is the brake switch +12v is present when brake is on
-White is ground 0v all the time

Also check that the blue wire has power at the connector at the back of truck once you find it under the dash. Corroded or broken may be an issue.

 

Thanx for the quick reply.I checked the controller and I have the settings you mention.the controller shows 12v at the Blue trailer wire all the time regardless if I push the brakes or not.Also the red wire does show 12v when the brakes are pushed.at the plug at the rear of the truck I get 0 on the controller terminal at all times.Also it seems that the controller settings don't light up or change when the slider is moved.I get a red dot when. I push the brake and that's it.do u think my controller is shot.If there's 12v at the Blue wire but not at the plug I must have a wire prob somewhere.any ideas on where to start.Again thanx for the reply

 

What brand of controller is it? Just checked my truck. Blue wire should only have voltage on it when brakes applied. The black wire has +12v on it all the time. Red wire +12v brakes on only. If you have a factory direct cable the connections under dash should be from left to right blk, blue, red, wht. If you have +12v on the blue wire all time something is not right, controller bad or different color wire is brake (maybe blk)
I have a Prodigy P3 Controller.

 

could also be a bad controller. see if someone with a similar truck will let you borrow thiers for a quick test.

 

thanx for the replies,if i remove the controller and put a 12v source to the blue wire to my truck,should i get a signal at the rear 7pin conector?i do think the controller is pooched but i waana troubleshoot the wiring also before i buy a new one,its a reese brakeman controller,looks pretty basic,nothing flashy at all haha

 

Yes that would work. Just remember there will/should be two pins with +12v. From the back, pin 2 ->brakes(bottom right and pin 4 ->battery(+12v)(top right).

I don't like time delay controllers as they apply the trailer's brakes full setting no matter how fast or slow you are going and in reverse.

 

I put 12v to the wire and no power at the rear plug.I checked wire as far as I could trace it.I gave up and ran a new wire from dash and back to the plug.now I have power to the plug.getting a new controller this weekend. Thanks for the wiring diagrams.

 

No problem as long as you got it going thats what counts. Happy camping.