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.
Yes, it could be relay or blown circuit breaker. Go to Winnebago website and locate the electrical drawing for your rig. Option is to follow the positive cable. Relay could be in the battery control center depending on which one you have.