I have an 02 Fleetwood Bounder, 2 roof ac units. Sometimes, on either unit, the fan will blow but the compressor will not come on. If I turn it off and back on again, sometimes several times, it comes on. And I can only run one ac unit at a time or neither unit will come on. It has a powermanagement system built into the thermostat and I think it has something to do with that system. Can I eliminate the power management system and install two thermostats for the ac units directly? Thanks.

IF you have a 30A coach (likely), you do not have enough power available to operate both a/c's simultaneously without the EMS. Attempting to do so will most likely either trip circuit breakers or damage the compressors due to low voltage. Or both.

Bypassing the EMS may work sometimes, but not in a predictable manner.

You should be able to run both a/c's via the generator. It is usually wired to provide a separate power circuit to the rear a/c so both can run.