You might have a bad start capacitor or a seized compressor on your rooftop A/C.

Rooftop units draw a huge amount of amps when first starting.

What gage extension cord are you using, and how long of a distance from your shore power connection? Too small of a gage wire or too long of a distance run would cause a voltage drop that would affect all the systems.

You May have a transfer switch somewhere that supplies generator power to the coach. Not sure how the newer units are wired up. Troubleshooting will be a process of elimination. I’m not sure how skilled you are with electrical wiring. It’s hard to diagnose these issues online.

Good Luck.  Fred

can't read the writing on the circuit breakers.  do any of them pop when trying the ac?    

   if you have an auto switch, you do nothing after starting the gen.  i don;t have auto switch so i have to plug the shore power cable into the gen outlet to use the gen. 

 makes it either or     shore power or gen

On 4/3/2024 at 1:10 PM, extech said:

anything that needs 120v ac power needs the power from the pole or a generator.    the converter  (120v ac to 12v dc) uses some energy to do its job, hence the heat.

 all the 12v stuff always runs off the "boat battery", the converter keeps it charged.'

  as said, the fridge runs on propane---no electricity needed.    the furnace uses 12v from your battery to run the fan

I posted pictures in this strand.