Yahoo Message Number: 11951 (http://groups.yahoo.com/neo/groups/Country-Coach-Owners/conversations/messages/11951)
Egon,
In the compartment where your inverter is, there is a solenoid that is for your battery charging system. When your engine is running the solenoid closes via an auxiliary oil pressure switch on your engine.
This charges both banks of batteries. When parked, your battery boost switch closes this solenoid electrically tying both banks of batteries together. I would guess you have a bad solenoid. This problem is fairly easy to troubleshoot and repair. On your model coach, the solenoid maybe in a different location, but it's there.
Fred Sage '01 Magna