[Fulltiming]

Agreed, the transfer switch would be the best place to start the search since that is the first common location for current from both the generator and shore power. If you have voltage on both legs of the output from the transfer switch, the main breaker panel is the next stop. Turn the main breaker off and back on to see if you have a partial trip there. I presume you are not seeing any voltage or current draw on one leg on the meters in the front overhead compartment. If an air conditioner trips out, the voltmeter for that leg doesn't register on my coach even though the remainder of the circuits in the coach are really live so make sure that the outlets and appliances on that leg are really out. If they are live but the meter is not showing any voltage, then check all the air conditioner circuit breakers.