I sent an email to fleetwood customer support and got the response below, very helpful information for other Fleetwood owners.
The battery disconnect solenoid is located in the battery control center
behind the PC board. The battery control center is in front of the coach
under the hood. There are two solenoids in there one is for the chassis
disconnect and the other is for the aux disconnect. Someone will have to
diagnose to see if the solenoid is bad or if you have a loose connection
somewhere in the circuit. We are including a battery control center
troubleshooting guide and recommend having a qualified service
technician or electrician do this repair.
Here is a link to the PDF file they sent along with the reply.
Battery Control Center Trouble Shooting Guide