Need 7 pin wiring help.
I have a 2003 Dodge Ram that didn't come with the towing package. I installed the reciever and am attempting to wire the truck with a wiring harness that came from Dodge. There were no instructions for some reason. It has a 4 pin that goes into the 4 pin on the truck. That part is easy. There is a purple wire that I need to splice in (I guess) at the back of the truck. I assume that I need to splice into the purple wire, in the group of wires, going to the tail light. Is this for the trailer brakes? Or is it backup lights?? Next on to the front of the truck. There is a red wire that goes to the battery (I guess). It has a fuse in between the battery and the back of the truck. Also a blue wire that I think goes to the brake controller that I don't have yet. I am planning on splicing the purple wire, connecting the red wire to the battery and leaving the blue wire loose until I get a controller. Is that right? Will my trailer brakes work, but just without being able to activate with the controller?