I saw a similar set-up on a Lark a few years ago. On the left side of the alternator was a wire lug (1/4") surrounded by a red disc. There was a two-wire plug with a black wire and a blue wire. On the right side was a wire lug (1/8").
This is a 170 OHC six-cyl with 3-spd auto.
Obliged for any help.

