Thank you for answering my post about transmission .
I had a similar issue with my ONAN shutting down and found that the sensor on the exhaust elbow was faulty. I had a spare and was back underway in a short time. Some Onans have a normally closed temp switch that opens when the temp is too high. If you have that kind, and don't have a spare, short the two sensor wires and it should start. If you have the normally open switch that closed when the temp gets too high, you can disconnect the sensor and it should start.
In either case, regularly check the temps at your oil filter and exhaust whenever running it until you can get a replacement.
Hope that's the problem on your Onan, easy fix.
Kent & Iris