Winnebago's equipped with the front/rear A/C selector switch and an onboard generator are wired similar to the block diagram below. This diagram shows the way that setup was done in our previous 30 amp Coachmen Class A, and also shows how I modified the wiring to add an external plug in capability for one of the A/C's. Your coach may have the two A/C's reversed from mine, but that's easy enough to sort out. All of my wiring changes were made at a junction box in the generator bay. I removed the cover, sorted out the wire sets to each A/C and then simply connected a lead and 20 amp plug to the front A/C in my case after disconnecting it from the generator. Next I added an extender section to the junction box and a 20 amp duplex outlet connected to the generator output formerly connected to the front A/C. In normal use, the plug is in the outlet. For dual A/C use on shorepower, the plug is pulled and connected to a 12ga extension cord to the 20 amp utility outlet. As I said, your A/C's may be reversed from that setup. It's easy to tell by which position your switch uses to run both A/C's on the generator. If you switch to the rear position, then the front A/C will be the one you want to isolate.
