how do dual alts work?

[Life is an Enigma]

AVBM II FOR GM 4 PIN OVAL ALTERNATORS

$179.00

http://www.mechman.com/accessories/avbm-ii-for-gm-4-pin-oval-alternators/

This would be easy to make to make into a standalone controller.

[Awaiting_Equinox]

I figured why call when theres a bunch of knowledge on here, maybe ill give them a call then. and that voltage control on tap. ill look into one of those also