Trunk Wiring Short

The dash light with the little car and rear illuminated lines has been on for quite a while. All the bulbs are fine and have been re-set. The dealer repair guy said the problem is the trunk wiring insulation has worn off and is shorted. I peeled the wiring from where it comes into the trunk for a couple of feet, and all looks well. If in fact this is the cause, where does this happen? Logic would dictate at the portion that moves when you open and close the trunk, but that checks out.

On some vehicles, there is a curcuit board in the trunk area which can go bad. Maybe the problem lies in this board.