Originally Posted by Pascal
I m pretty sure the mariner is a twin engine boat, isn't it? How can there be only 1 batt switch for 2 engines, 2 batteries plus house loads....
Doesn't make any sense. There is no way two engines could be connected to a single batt switch.
My guess is that there are another 2 batt switches in the ER for the engines and that the switch in the saloon panel is a house selector.
Very common on smaller boats that will often not have a gen and all batteries (generally only 2) are used for starting and house. That way you can save one battery while at anchor with the fridge and stereo on.