Onan Generator 7500 Quiet Diesel

Having problems with my generator, Onan 7500....runs OK until I turn my A/C on. When it loads up the generator will run about 5-10 minutes and kill.
I am getting three blinking lights on the switch after stopping. According the manual it mentions abnormal maintanence problems. I will bring it to a Onan dealer in the morning but was checking on any suggestions available information from those that may have experience these issues.