Someone esle will probly know more, but when i was installing some equipment up front in the truck i found some wires that were labled for brakes, and watever else there was, but they were cut and stoped there, with only several others continuing. I have the base model also. The connector in the back of the truck is a 7 pin i think and all seven had wires connected to them, dont know where the wires come from though. They are probably not connected to anything since i saw them cut inside.
Cant really help you out though.
