Genset (2016 Tiffin RED PA37) won't start.

If it hasn't been run for a while, my manual says to hold the switch to the off position for about 30 seconds to prime then go to start.

Genset normally uses the HOUSE battery (NOTE: at least one Motor home the genset has a battery all to itself, do not know which models that is)

Normally when driving the ENGINE ALTERNATOR charges both the chassis battery and the HOUSE/Genset battery.. For some reason it appears yours did not.

Suspects include
Cut off switch in DISCONNECTED position (Aux battery off, Use/Store switch in Store, or however they labeled it, varies from RV to RV)
Bad isolator device (This is the device that connects the house to the engine for charging,, may also connect engine to house when shore power or generator running)
bad Battery
Bad connections

All the interior lights on. (or at least enough of 'em, each 2 light incandescent fixture draws about 3 amps)

Since it's a 2016,, Warranty may apply if bad______

For now, On the dash is a button may be labeled AUX START, EMER or Emergency Start, or BOOST,, Press and hold for 30 seconds, then try to start generator, Do not hold for more than a full minute.. Once generator starts hold till the auto transfer does it's thing and lights brighten.

Have you gone outside and tried to start the generator with the switch right on the generator itself?

Wayne had it right!! That was it. Thanks Wayne. I owe you dinner!!

Thanks everyone for your input. This site rocks!!!

I guess you mean that after holding the start switch down for 15-20 seconds the genny finally started?
The light on the start button flashes as the generator is cranking!
It stays solid when running!
If you use the start button on the genny itself, you should press and hold it to prime the carb, and then press it the other way after 20 or so seconds to start. Good luck11