Battery Cut-Off Question

[Marinelender]

Need some electrical help here.

Brand new deep cycle batteries in our '03 Journey (3 X 12V). The dash cut off is allowing something to drain them over time so I want to completely cut them off for storage purposes. I bought a battery cut-off switch but I have two ground connections to the batteries and two hot connections, so I don't know where to put the switch....can anyone help? Thanks in advance....Jim

[Chuck 1935]

One set of wires should be for the starting battery, The other is for the house batteries.
The switch on the dash connects ALL the batteries together to start the engine or generator if one set of batteries are low.
The top slide out tray is for the house batteries and the bottom tray is for the starting batteries.
The house batteries might have things like the bedroom clock draining them over time.
I aleays keep plugged into 110 volts when my MH is not in use.