Alternator Q

I recently purchased a one wire alternator from a rebuilder on ebay. It's actually a late model Ford alternator that was re-wound for 100 amps and had a v-groove pulley installed instead of the poly-v pulley. My question is:
This alternator has the one wire terminal on the back, but also has a three prong weatherpack type connector. Is this connector anything I need to be concerned about? Is it for the OBD system and maybe an ammeter feed? Anyone with knowledge of this?
All help appreciated!
Thanks,

Jim Vogel
Tallmadge, Ohio