Hmm good question. Try taking the regulator and the harness, door panel for the switches power mirrors if he has them. I believe if u folow the harness from the door to the body it will eventually run into the side of the dash. It shoud plug right in but dont know if itll work. It maybe as simple as putting a fuse in the fuse panel if not just run a switched ignition off the fuse panel. Been thinkin of doing this on mine. Hope this helps