Running a converted alternator

If you insist on that, the basic diagram you posted tells you. It is actually a simplified diagram of original wiring scheme. You want the battery only on one side of the meter, and "everything else" including the alternator output on the other side I'm not sure the ammeter you mentioned is any better and might be worse. I've seen lots of these with winches, electric plow lifts, or even just off road lights melt the innards of the meter. They look exactly like the one posted on the MAD page I posted