I have a 1995 Safari Serengeti with a propane Onan 6300 watt 52 amp generator. I have a problem. The generator will not run one of my roof a/c's. I checked the voltage at the auto transfer switch, 128 volts. When checking this I found that the auto transfer switch was not engaging. I could manually push in the switch, but you could see it arcing. Sparks are bad so I purchased a new auto switch, thinking this was the cause of my problem. Installed a new 50 amp transfer swtich. It would not switch automatically on the gen side but worked on the shore side. So I jumped the gen switch, a/c kicked on smoothly and was working. Had 120 volts in the kitchen outlets. After about 10 minutes of the a/c running, I am guessing the compressor cycled, the a/c compressor would not restart, it would growl/stumble all of the worst a/c sounds. I shut off the a/c, checked power at the gen still 128 volts. When I am plugged into shore power both a/c units work as normal. Here is where it gets interesting. When I am parked I use a $300 Champion 3500 watt generator plugged into the shore power plug, the front a/c works as normal. I have used this set up on 100 degree muggy Nebraska days, no problems at all. I have also installed bigger start capacitors on both generators. What am I missing here?