what does voltage regulator do?

I posted a while back due to overcharging issues. I got it mostly resolved, but the volts were still a little higher than I would have liked.

Today, I installed a new voltage regulator since it's the one thing I haven't tried. Now, the voltage on the field wire seems to fluctuate. Meaning, I'll show 7v, 12v, 5v, 15v intermittently.

I can't remember what it should specifically show, but I will assume this isn't right.

Im now getting 15.1-15.8v charging at idle.



This has the madd bypass. Terminals cleaned as good as I could get them. Minor voltage loss to the ign side of the regulator.