Plug in truck bed or use plug in bumper for 5th wheel

I have an old 2012 F250. On that model the rear bumper harness used a plug to connect to the harness coming from up front. As i recall, Bargman mane an in bed harness that got its connection by acting as a sandwich between the rear two plugs. Then you cold get different lengths with 7 pin RV plug molded at a 90 degree angle for install where ever you wanted to drill in the bed. I moved mine up toward the front of the bed and it is not hard to reach on my 2 wheel drive puller.