Jim,
I know what your problem is, but the only way that I can see to access the contact board in the reel compartment on your coach would be through the rear of the enclosure via the engine bay access door. My 2000 Marquis has a bedroom slide, so I can access it through a removable door in the floor of the closet above it.
The wire from the switch to the contact board on my coach was spliced at the factory. That splice was what failed on my coach. So when my switch quit working and I was trouble shooting it, I found the corroded butt connectors in the middle of the wire that you are trying to replace. If you decide to splice the wire, be sure to check for a factory splice, and splice it in that location by cutting out the original splice.
Gerald