I have a 2007 Keystone. FWC gave me measurements from the outside front edge and drivers side edge to where the wires should be. The distance was close but not quite.
I found that the wires were routed up the drivers side overcab area behind the lift panel then between the styrofoam insulation and the aluminum top and past the front vent along the drivers side of the vent frame.
I removed the horizontal ceiling lift board, which is aft of the front vent.
I went to the top of the camper and at the spot from the front and side edges I drilled a small pilot hole down through the headliner.
I then went inside the camper and carefully cut an X in the headliner so I could open up a hole in the styrofoam insulation - it tends to crumble rather than cut so be careful.
I could feel an aluminum plate with a circular hole in it between the foam and the camper roof skin. Turns out the wires went up through that hole and were coiled up. The pilot hole came down through one side of the 1" diameter hole in the aluminum plate. That was good!
Once I got that hole enlarged I could feel the wires and then after feeling them I was able to use a bright flashlight see them going up through the hole but they seemed to be stuck between the camper roof and the insulation. I'm glad I only drilled a very small pilot hole down through the top!
That is when I went on the roof and started feeling around. Knowing where the wires were going through the hole and the direction the wires exited the hole I could get a sense of what I was feeling under the roof skin, turns out the loop of wire was only a few inches away. I could easily feel the wire loop.
I flexed the roof a little to try to free the loop up and then fashioned a small paperclip hook to grab the loop from the inside of the camper up through the hole in the headliner. It took some firm tugging to get it to slip free - I may have actually used some pliers to get a firmer grip on the wires to pull them down. (easy does it!!).
I do not recall at the moment if the wire ends were terminated or not. They may have been taped together but I think they were hanging up on the styrofoam.
So recapping:
If you drop the camper top and get on a ladder you can press down on the top and feel the wires under the thin skin of the roof (at least I could). That helped me located the end and the loop of wire which was about 3" away from the hole I cut. That should help give you confidence about fishing or pulling the wires out.
After I got everything hooked up and checked out I bought a vinyl patch kit that has a small piece of cloth in it and used that cloth as backing behind the X in the headliner as I glued it back together. Once the horizontal lift board was replaced everything was covered up.
I will look for the pics I took.
Hope that helps.
Craig