Troubleshooting the chassis to house charge solenoid

[tom1957]

I have a 2020 Intent 28Y.
The house batteries are not charging while driving. Many suggest that the solenoid is bad. Others suggest that there is a fuse that could be blown. So...

I have confirmed that the alternator is charging (14.4v).
I have confirmed that the batteries charge from shore power.
I have confirmed that the batteries charge from the generator.
I have confirmed that the solenoid works when the battery boost switch is pressed.
I have confirmed that the solenoid is NOT activated when the ignition is switched on.

QUESTIONS:
1. Where is the fuse located that is being talked about?
2. Is it enough to put the ignition in ACC or do I need to start the bus?

Any assistance is greatly appreciated.