On the 30 AMP MH Fleetwood used a EMS to run both AC's at the same time.
They usually used a 11K PS Coleman
(9.9 Full Load Amps) in the rear and a Coleman PS 13.5K(11.2 Full Load Amps) in the front. Total AMP with both running 21.1
If you ran the microwave when both AC's were running. The EMS would shut one of the AC's off until the micro was done and then turn it back on.
My MH came that way. But since I replaced the rear 11K for a 13.5K and the front 13.5K with a 15.5K heat pump. I then put a separate breaker box in for the front AC
Since the OP has a Fleetwood. He needs to find the owners manual for it.
And it will explain the operation.
He can download a PDF HERE for his Fiesta