Originally Posted by str8strm
1985 345 motorhome, we plugged into shore power, and 20 minutes later ...lost shore power. We checked all the breakers, and could run the generator and power the microwave, etc.
The Genny runs through the same circuit breakers on the main panel as the shore power...I would suspect either a bad contactor in the shore power recoil can or the positive contactor in the bedroom that connects/disconnects the shore power/generator electrical sources to the main panel.
If it were me, I would get a copy of the wiring diagram and start tracing the shore power voltage from the shore power connector back to the panel.
From your description there has to be an open circuit somewhere.
Luck - let us know how it goes.