Just wire it up and see what happens. You won't hurt anything, it'll read backwards if it's wrong.

But, I THINK that the pos side goes to the battery and the neg side goes to everything else.

I'll crawl under the dash on mine (it's a little older, but an ammeter is an ammeter) and have a peek. I'll let you know.

~#~#~#~#~
1946 Chevrolet 3600 - "Old Number Seven"

Cavalry's Here. Cavalry's a frightened guy with a rock, but it's here.