charge circuit from alternator wire (1 Viewer)

[rdang]

I've almost completed my dual battery install on my 100, I am using this one here:

Slee - Dual Battery System (Toyota 80 Series Land Cruiser)

There is a wire from the relay that is supposed to be connected to the "alternator good circuit" but I can't figure out where that is. I see 3 wires from the alternator going to the little fuse box by the battery, but I'm not sure if I should be using one of these wires.

Thanks for the help.
Rick