That's what I thought. I'll have to check it after it warms up real good for a while. Yes I repaired the original Moto alternator, it does the same thing and yet the same with both regulators. I'm going to remove the JD type connectors and that 4 pin connector and put some new insulated male/female connectors on each wire, at least that will get rid of any 50 year old connectors in that circuit. I could also just re-wire the alternator to regulator harness with a separate harness if that doesn't seem to help, but so far today the idiot light is going out today.
Actually that idiot light is wired across the 'isolation diode' so if there's no charging there's something like 10-12V across that light. If it's charging properly, there's only 1.5V across the lamp and that's not enough to light it. I'd been looking on line for some of those lamps and boy they're expensive. I finally stopped in an auto store and got 2 of them for a couple bucks.
I couldn't find anyone that would pull the center race off the Moto alt. shaft, so I was talking to my neighbor and he had a $10 HF 3" carbide wheel. I cut it off with that, cleaned it up, installed the bearing in the front part with the keeper ring and pressed the assembly on the shaft with one of those rings you put on the implements to fit the larger JD draw bars. It was just the right size for that inner race of the bearing. I'll have to get one of those HF grinders.