It gets more interesting hearing what the fault codes are indicating. Sounds quite different from what I'm used to fault code wise with my Progressive EMS.
I didn't see where you have run the AC off of shore power since you put the new surge guard in. Knowing for sure it works when hooked to a known good electrical outlet would be helpful in trying to narrow it down to surge guard, ac unit, or generator. Also, are you using any adapters on the end of your power cord to connect to the generator, ie. a dogbone to go from 50 to 30 amp etc.
