Couple alt/reg questions

Sorry for the dumb questions fellas. New to me car and trying to iron
out the po's stuff.

I have a 1 wire alt that is not charging.
12.5 V on both the battery and lug on the back of the alt.
Same 12.5 V to the bottom of the regulator (I think).
The pic of the firewall is where i got the V reading. I read the V
off the bottom of the box (blue wire) as the top was 0 (green wire).



The second pic is of the alt. I don't think the po finished the 1 wire install
as there are 2 more wires laying off to the side. None of the spare wires has any voltage to them but I will have to confirm that.




Any ideas or hints?

Thanks