On my 2001 Damon Daybreak when the switch is off there is 12V power inside and the batteries are not being charged by the converter. With the switch on the batteries are being charged. It has a BIRD so the chassis battery is charged also if needed. There are those that may say you can't have 12V inside without the batteries on. But as you know, you can. Thanks for following up.
2016 Wildwood 28RLDS
2014 Tundra 1794 Platnum,"23" T-Bucket
2011 Harley Softail, 2010 Spyder RTS