Originally Posted by Prairie
Thanks for the responses. It's about what I expected. Trouble is it's a real pain in the ass to get to the batteries under the lounge seat. How about removing a fuse in the DC panel to disable the circuit that serves the parasitic load?
On the 2010 Interstate, the propane solenoid might bypass the main disconnect (not sure what year they fixed that). That would be about a 0.75 amp draw, or 18 amps per day. With two house batteries totalling 160 to 168 amp-hours, your house batteries could be stony dead in about 9 days from that draw alone.
Another possibility would be if you have left the inverter turned on. You have to shut off the inverter as well in order to prevent parasitic loads on the AC side, such as your television(s), which draw some power even when turned off. Note that even in "charge only" mode the inverter/charger will draw some power, for monitoring the batteries and its own cooling fan; it has to be "Off" to eliminate any draw from that source. Since the remote control doesn't have an "Off" position you have to do it from the switch on the front of the inverter/charger under the sofa.
Yet another possibility is the antenna amplifier in the full-width compartment over the driver's seat. On older Interstates, the amplifier isn't shut off by the battery disconnect, either, and so has to be shut off separately.