No luck with the new regulator; still acts the same at the original and the first replacement.
I did put my DMM on the diode check function and test for the forward voltage drop of the diode. I could only get one reading on a particular pair of pins, but the readings matched between the replacement regulator I got. For the original regulator, the drop was a little higher, but not by much.
I measured the charging coil and lighting coil resistances of the stator again. For the charging coil (white wire), I got around 1.2-1.4 ohms (spec is 0.2-1.2 ohms @ 20C). It is a colder than 20C here, so maybe that affects the reading. Not sure if 0.2 ohm above the spec is bad or not. Got about the same difference for the lighting coil (yellow wire).
I removed the regulator and checked the VAC from the charging coil and lighting coil. At idle, the lighting coil (yellow wire) had about 18 VAC on it, the charging coil (white wire) had about 22 VAC on it. At higher RPM, the VAC increased. Oh, and in the process I blew out my tail light because of the high voltage.
With one of the replacement regulators installed, I checked the VAC on the yellow wire. It stayed steady at about 8 VAC at any RPM. Not sure if that tells us anything.
Any other tests or check you can think of doing, Zombie? I'm at a loss.