RobbieH
On my '03, I ordered it w/o towing pkg because I knew I'd be doing after mkt rear bumper/hitch. I got a Prodigy and pluged it in to the connector under the dash and then just ran a single large wire (#10 I think) from the output of the prodigy to the rear of truck and tied in to the trailer connector. I don't remember where I tied into for the trailer lights, but think there was some kind of factory "place" at the rear of the truck. The four conductor connector is tied into that same bundle of wires & I stuff it up under the bumper till I need it for smaller trailers w/o brakes.
RandyN