It seems to be charging erratically. I'm guessing the regulator is going. This is an OEM 11 Corvette alternator.

 

Seems to be rock steady at 14.2 volts DC. Does it read anything for AC volts that might indicate leaky diodes in the rectifier?

Rick

 

Good question. I'll have to use a different meter to see. I see it is consistent, but my thought when I saw this was that maybe the Power Probe isn't sensitive enough to show a very fast split second drop.

 

What happens when you increase the engine RPM? What happens when the fans and air conditioner kick on? Your 14.2 VDC number is about what I see at idle when my radiator fans and fuel pump are running. About 14.4 VDC without the fans running. I don't yet have anything else electrical running on my El Camino but will someday.

Rick