What is the black box on the back of the alternator? It has two screws coming out at the bottom and like 3 wires running through it

 

Just an insulated connector. Why they felt the need to make it like that, I have no clue.

 

so can I leave it unscrewed to the alternator because that’s where I’m gonna need to connect the external voltage regulator

 

Yep. That will set the check engine light though.

 

Installing the external voltage regulator. I can’t find a key on power source or a fuse any help would be great

 

Here’s a pic of my fuse diagram

 

I think the asd relay output would be the best spot for it. C212 is right after the ignition switch, S201 is where it goes into the fuse block(before the fuses). Ideally i would see what kind of amp draw the regulator pulls and make the decision based on that. It may need it's own fuse.