Question Diesel generator in 2014 Prism

[Djhcat]

I bought my motor home used from a dealer. When I got it he had the generator running and it worked. Since then I can not get it started. The control panel does not light up, and in very faint words it said low battery 8.3 Where does the battery power come from? Is it the house batteries or the truck? All the batteries are at full charge.
I crawled all over under the coach and cannot find another battery or trace where the battery wires are coming from.
It is a diesel generator (yuck). Any ideas anybody?

 

[Dona40]

Check for a tripped circuit breaker in the house battery compartment. Mine tripped once. No leveling, slides or Gen.
I thought it was big trouble until I found it.