I do not know how, but I lost all 12V in coach. I have 12v when the gen is running but if I turn off gen the 12V is off. I can not locate master switch - if any.
Sounds like battery disconnect is in off position. Should be switch normally by the entry door to energize battery disconnect relay. Some Winebagos have battery disconnect behind the entry step. As I remember that is wwhere your batteries are. There is a small metal plate to remove to show disconnects. Sounds like blown fuse. Some battery disconnect relays have fuse mounted to them.