Need some ID's

I doubt you have 2 Vreg's (read post #10). If you want to clean up the wiring, I think it is simplest and clearest to put the Vreg near the alternator, with dedicated wires between the two. Mine sits on the inner fender recess right beside the alternator.

Wire +12 V ignition power to one field terminal (either one, blue is "factory" color). I connect Vreg "sense" wire (blue) to that too. The Vreg's "low-side control" wire (green) goes to the other field terminal (verify I didn't mix up green & blue). Finally, I ran a dedicated ground wire (blk) to the case of Vreg since I don't rely on rusty screws like the factory did (causes many problems). I can sense right at the alt terminal because I supply it from a thick blue wire that is switched in from the battery by a relay. Ideally, you want to sense BATT+, but don't connect directly or it might drain down your battery overnight. Vreg tries to maintain whatever point you connect to the sense lead at ~14.3 V (relative to its case).