Jim, unfortunately (or maybe I should say fortunately/w3tcompact/icons/wink.gif), a lot of my experience is dated. I never had one of those wiring harnesses; had to just run the wires to where they were needed myself. If I were going to do it now, I'd have to order one of those harnesses and see how it worked. Like Gordon said, the controller should have 4 wires; (1) ground, (2) hot wire when the key is on, (3) tapped into brake light, and (4) back to the plug connector on the rear of the vehicle (and therefore on to the brakes on the trailer).
<font color=blue>I have a 6-way plug already mounted on the truck that I use for my other trailers...would the brake controller connect to this recepticle?</font color=blue>
Yes, assuming it really is a 6 prong plug (and all the ones I recall on the vehicle were); you know they make some "adapters" for 4 wire trailers that have what looks like a round 6 prong connector, but not all the holes have a metal contact in them. So, if you already have the other wires hooked up properly to that 6 prong plug, then the contact that isn't currently being used will be the one for the brakes. There is, of course, a "standard" sequence or arrangement for which wires go to which contact, but I'd have to look at the instructions to remember what order it is now.
Gordon has not only probably done a lot more of this than I have, but also more recently, so maybe he'll clarify, confirm, or correct this for us./w3tcompact/icons/laugh.gif