[rdlamb]

Ron:
Do you have 1 or 2 breakers on the generator?

Mine has a 37 amp x 2 single breaker. It went out. As explained to me via Cummins/Onan the breaker sends out 2 lines, capable of 37 amps each. When you run 2 A/C(s) you may exceed the 37 amp load of one line as the start up of both A/C(s) draw a lot of amps.

The switch blew one line. The generator would run fine, but no 110 output.
I checked the transfer switch (under your bed), and no 110 in from the generator. Fixing a generator was out of my league, so a service call ensued.

Onan replaced the switch with a "newer" or "improved" switch, and everything seems to be running well.

Always seems to happen when it gets hot outside. Mine went out during the 8 weeks of 100 deg + weather that cooked San Antonio last spring.