Entertainment system wiring
 

Could someone please help me with a wiring issue. I have a 2008 Caravan SXT. Factory it came with the RES headunit and I have bought a dual screen overhead console and VES dvd player that were sourced from a 2010 T&C. I know I still need to purchase the REN head unit to even get this to work but if I can't get someone to help me with the wiring issues I'm not going to bother with it. My problem is, I bought the harness that plugs into the head unit, VES dvd player then stops @ the passenger A pillar. I have also bought the harness that goes from the overhead unit to the driver side rear panel that will have the inverter and input module. What I can't find for the life of me is the harness that
goes from the passenger A pillar to the ovehead console. What I find strange is that the harness that hooks into the head unit and dvd player does not hook into any power source that I can see. Please help if you can. The harness that I bought is part #68062445AA which is a 2010 T&C.