Assuming it's similar to mine (which may or may not be the case, as I'm not in a position to check the model number), there's a small (5A?) DC fuse on the little control panel on the generator itself, next to the start/stop switch and the AC circuit breaker.
The main DC power feed to the generator is of course a much heavier wire, and wired more or less directly to the battery of the coach (in my case, the chassis battery, though the house battery is also used sometimes). This connects to the solenoid for the starter, and thence to the starter, with a wire for the control power for the generator also attached to the input side of the solenoid.
If you don't have 12V power getting to the starter solenoid, you obviously won't be able to start the generator. That may be switched by a battery disconnect switch somewhere or some similar arrangement.