I have a flat four pin trailer wiring connection under my back bumper. I bought this truck used, so I am not sure if it is factory installed, but it looks like it is.
My question is if I have to run new wiring under the truck if I want to use the RV round connection that is installed into the back bumper of trucks that have the towing package? I think that one is either 6 or 7 pin. Is there an adapter to connect the two? I think the extra pins on the round connector go to the electric brakes and they would not work if I was able to connect the 4 pin to the round connector. Any ideas?

 

you will have to get a brake controler and then you can get an adapter for the round plug the adapter fits right into to square spot next to the license plate and has a four pin plug that connects to the plug you already have (that control the lights) and the other wires connect to the brake controler.