I used a test light to find which wire was "hot" with the key on. Once I found one, I just spliced to it...not sure what the wire went to. I bought my mounting plate from Gorilla and with it mounted, the contactors will touch the angled brace that goes to the bottom of the light housing (there is no 1/4" clearance). I cut a small piece out of a garden hose and turned it inside out (green on inside, gray on the outside) and wrapped it around the brace and ziptied the hose. This works as a spacer and the winch will not ground out. Works fine so far and you do not even notice it. I have had some problems with the rocker switch. If you hold it down and let off, it will sometimes continue to reel in. It might be designed this way (doubt it though). If not caught, the winch is so strong that it will pull the hook throught the roller fairleads and bend them.