If you are still out there the first thing I would do is have someone, any auto service center, check the coach batteries. I suspect they are dead. Newer vehicles have so many things running in background that the batteries often go dead in a matter of weeks while sitting. This is more common with the truck batteries than the coach but still worth checking. The gas monitor may have been the cause.
As for the AC if it was a cool day, very little load on the unit, the coil may have frozen over. If the AC works after you have been shut down for a few hours that would confirm this. This is an indication of a low charge in the AC unit.
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles