microbe,

So your handy dandy new alternator shows a output of 16 volts...! That's too much. The regulator should top out at 14.7 or so.

You must have a beastly VOM to measure 20 amps. I have a plethora of meters...Simpson to Fluke, and they max out at 10 amps. Did you series some type of shunt when you measured this.

Something is haywire...16 volts is way too much.

Stuart