Generator won't keep running
Would appreciate suggestions as to why our Onan generator (5500) won't keep one air conditioner running when going down the road. It starts okay and runs for 15-20 minutes and then just shuts off. Water heater is off; refrigerator is on Propane, so there should be enough power. Outside temperature was in the 80s, so not overly hot. Gas tank is full. This is an on-board generator for our 2006 Georgetown 319TS.
Also, when we look at the troubleshooting section in the Generator manual, it mentions several different troubleshooting codes and what they mean. Any ideas on where those codes might appear?