!2 or 24 volt?
I have a 1999 Dutch star diesel pusher rv with a freightliner chassis and a cummins engine. Both 12 volt engine batteries seem to checkout as good, but if I drive just a little unconnected from the charging ac system it won't start unless I use the battery boost. The battery boost jumps from the 2-6 volt batterys to the 12 volt. Should My engine batterys be wired 12 volt or 24 volt?