I went out yesterday and stopped at a dealer on the way out to pick up a brand new line. They had an 8' for about $36 and a 10' for about $53 so I ended up going with the 10'. I figured it was better to have too much cable because you could always hide the slack somewhere. Anyway, here's a shot. The only wire that didn't get cut was the yellow.
The line didn't terminate into a junction box. We had to get into the front seat of our dinette and then remove a piece of wood panel that protected the wires. The wires were just joined with wire nuts. I took a pic of the original wiring just in case something didn't come out right.
Before putting the dinette back we backed the truck up to test the lights. Wouldn't you know it, no lights! It took about 2 minutes before we realized the plug wasn't all the way into the truck. The lights came on as soon as we got the plug correctly seated so all is well. In the coming weeks we will probably look into splicing the old cable and keeping it the camper in case this happens again. We plan to strap the line to the frame now to remove most of the slack.