trailer brakes

[RK55guy]

i am having issues with my trailer brakes and or control box. my truck was factory wired for trailer brakes with a plug under the dash. i bought a hopkins control box and the adapter harness to connect the box to factory plug under the dash. as soon as i hook the plug the control box in my brake lights on my truck come on and when i plug the trailer up the brakes engage. makes me feel like the plug and play adapter harness may be wired wrong. any info will be appreciated.

 

[aczlan]

What year and model truck? What model number Hopkins box?
I know that when we put a brake controller in our 2005 GMC half ton there was a pin that was left out which you had to put in a different hole depending on what year it was.

Aaron Z

 

[RK55guy]

its a 2001 dodge 2500 cummins. the controller is 47235 and the adapter is a 47755

 

[AllDodge]

its a 2001 dodge 2500 cummins. the controller is 47235 and the adapter is a 47755

Shows the correct items, what trailer connector is on the truck (6 or 7 round)?

 

[RK55guy]

i am not sure if its a 6 or 7. how do i tell which one it is.

 

[Birdhunter1]

The trailer side of a 6 round will be like a 1” or 1 1/4” size plug and have 6 round holes where a 7 pin will have 6 slots running (roughly) parallel to the outer edge of the plot as well as a receptacle to go over a stud in the center of the plug on the truck, the whole contraption will be closer to 2” diameter.

 

[RK55guy]

ok, i will post what i have tomorrow. electrical stuff drives me crazy. thanks for yalls help.

 

[RK55guy]

going by birdhunter1’s description, i have the 7 pin on my truck and it appears that the plug from the trailer should match up when plugged in.

 

[thekkfan]

Is the 12v pin in the harness at the brake controller have 12v all the time, or only when you hit the brake pedal?

If only when you hit the brake pedal the 12v and brake wires are crossed either in the harness or miswired in the truck. That would explain why you have 12v all the time on the brake wire.

 

[LouNY]

there are so many different wiring diagrams and trailer connectors, between round pin and flat, 6 or 7 .
if you goggle trailer connector pin outs you can find all the different ones and the color codes.