Onan generator doesn't work

The Jayco 2-year warranty does not transfer to a second owner, but the Cummins/Onan warranty does. This does sound like a battery issue, but if something else is involved, you are covered by the Cummins/Onan warranty completely for 2 years and a limited warranty for the third.

https://power.cummins.com/sites/default/files/PGBU-Warranty-Statement.pdf#page110

There are Cummins repair shops across the U.S. Had to take ours to the one in Kenly, NC for a fuel pump replacement under warranty. Good luck.

Sure sounds like low battery or loose connection to battery. Get a multimeter like westend suggested and check voltage at the starter relay or starter (starter is better place, but can be hard to reach) while you are trying to crank over the genny. The "meter" on the wall is about worthless for giving you anything more than very rough battery state indication.

Meter says 100% for house battery and 60% for truck battery. Would the truck battery affect generator? Also, I'm hooked up to shore power now, so would this give an inaccurate voltage reading for house battery? Thanks for your advice.

X2 Make sure the batteries are fully charged and all cable connections are clean and tight. Can the dealer look at it?

Do you have a hand-held meter?

Battery needs charging.