RE: Help--Build A Charge Jack Into The Bed Of My Truck?
Why not get a remote cigarette lighter that is designed for outdoors. Get one that is designed for a boat--so it can take the weather. Mount it just under the rail wherever you want it.
Then, go back to wal-mart, and buy an adapter that plugs into the cigarette lighter, and has two female bananna ports in the end of it. Problem solved.