Generator Woes, Onan nhe emerald + 6500

While driving down the road with generator running and the air conditioner on and running, suddenly the electricity goes off, I jump out and realize the generator was still running, drive on and suddenly air conditioners come back on, run for a while and then go off, this includes all the electricity, the refrig switches to gas when the power goes out. I ruined my starter motor on the genset before I realized what was happening, but, I know how to fix that. I am asking help. Not to take it to a dealership of some kind. What kind of thing could be happening to make the electricity go off and on like that?