You'll need to look for the Ram Body Builder PDF for a 2007. It will show the location and general description of any pre-wired sockets in your truck. It will also detail where missing harnesses would splice to. If you look in the Tech sub-forum, I have a post with 2005 Body Builder wiring pictures. It's probably generic enough to give you ideas of what's missing and how to incorporate it. The year-applicable Parts Manual will have part numbers for the necessary harness jumpers. Know that color codes/features/methods of actuation might change from one year to another, and CANBUS might be an issue on some things.