Alternator output 15V?

So I just got the SR20 running in my buddies FC RX-7 last night, starts up great, runs awesome, everything functions as it should.

Except the alternator, its producing 15v. A bit too much for my liking.

Does the 2 pin connector on the alternator need to have both wires hooked up? One is a 12v constant and the other is for the charge light on the dash. I put the 12V constant right to the output post on the alt seeing as that it is a 12V constant source.
The charge light wire I left un-hooked.

Maybe the voltage reg inside the alt is fried…

sounds like the internal regulator is done. New alt time!