I'm about to configure my 97 Plymouth van so that it has two batteries. The second battery will be kept in the rear of the van in a battery box with a vent through the floor. I'm using a Mega-Tron RV-Marine Deep Cycle 12v battery, which will provide power to a medical device at night. I bought a Valmar (Model 31122) battery selector switch. The switch has four settings: Off, 1, All and 2. I suspect that 1 means batter 1, and 2 battery 2.
I have a pretty fair idea how to install it ignition and ground wise. I know the difference between +/-, for example. I'm going to need some wire to go from the rear to front under the chassis. Does #10 seem right? I'll try to keep it tight and away from the fuel tank. It seems best to put the switch inside the engine compartment. I think I'll be able to drill a 1" or so hole through the floor in the rear of the van. Maybe I'll call the Plymouth and ask for advice on that. Any suggestions or comments on all this?
I plan to put a 30A fuse inline.