Originally Posted by RRB
We have a main power on/off switch down on the left wall as you enter the coach. I was told it needs to be on to charge the batteries.
My 5270 BT Cruiser has the same switch, so with the switch off, the 12V disconnected, I put a voltmeter on the house battery terminals then plugged in to 120V shore power, it then reads 13.47V which indicates to me that it's getting the current needed for charging. So I typically charge the house battery with the 12V switch off - if I'm not using the coach that is. Yours may be wired differently.