Our Jayco is a 2003. I like the way the radio can play when the engine is running and the house battery is turned off, or when the engine is off with the key removed and house battery is on.
If it's parked more than a few days with the house battery on, the house battery will be discharged. If I turn the house battery off and make sure all the engine stuff is off, the Jayco can sit for a couple months without running the batteries down.
There should be a House Battery Switch, probably by the house entry door. It actually controls a Latching Relay near your House Battery(ies). IF for some reason, that Relay is NOT disconnecting when you ask it to, that's your problem.
I usually leave a ceiling light ON so I can see the House Battery go OFF when I hit the Disconnect.
You should NOT have to go out and physically disconnect the House Battery.
If God's Your Co-Pilot Move Over, jd
2003 Jayco Escapade 31A on 2002 Ford E450 V10 4R100 218" WB