WinnieView

Most need 12 volts DC for the control circuitry whether on shore or battery power. 

This is the fuel pump you need and with some basic tools and skills it can be replaced  in about 30 minutes or less;

https://www.amazon.com/Airtex-E11015-Electric-Fuel-Generator/dp/B0076D5OI2

Just now, Kirk W said:

I wonder if the problem might be that the generator is overheating when sitting still? Onans have an over temperature shutdown. I would look for something that might be restricting air flow when the RV is not moving. Where is the generator located in the RV?

If that's the case then the fuel pump needs to be replaced. When we had a 5500 it would only run 10-15 minutes in temperatures over 90F until we replaced the pump.

You may want to checkout https://www.ownersrental.com/

You may want to have your coach batteries tested, and check for any tripped breakers on the converter.