Need 50 Comm. Regulator Help

My 50 Comm 6 is not charging. I ran it with the battery neg. terminal grounded, which caused the problem. I flipped that battery around to pos ground. I polarized the gen but no help. I wanted to swap out another reg that came from a 50 Pacemaker to see if that would help.



The 2 regs are different.



The reg that's on my Comm has the A, F & B terminals...but it also has a lone single terminal at the top directly on the opposite side of the B. This lone unmarked terminal confuses me. A wire is attached to it and joins the wiring that goes thru the firewall.



The reg from the Pacemaker doesn't have this extra lone terminal on the top.

I checked and the lone terminal is not hot. Switch the key on..still not hot.



If I swap the reg. I have nothing to attach this wire to.



Can anyone shead some light on this?



If I convert to an alternator with internal reg....what would I connect this lone wire to?



Thanks



thekid