Diagnosing high voltage

Then it HAS to be that the green wire is shorted (to ground) OR there is a problem in the alternator.

I removed the green wire from the alternator and it’s still charging, so there must be an internal problem with the alternator.

I guess I’ll be returning a brand new alternator.

I checked the brushes at the time of purchase and the was no continuity to ground on either brush.

Must be some other possible internal problem with the alternator?
This was a good learning experience.

I removed the brushes from my “new” alternator and installed them in the old one. When I removed the old brushes, the plastic had deteriorated on both causing a short. One of the brushes was only attached by a thread. There was also dust and debris piled up against both brushes, including a relatively large metal filing.

So far so good. Charging is stable and all lights and electronic accessories are functioning very well, including my factory gauges.

Obviously having a voltmeter or ammeter installed is critical, otherwise I wouldn’t have caught this until it was too late.

I think I’m going to keep the new alternator and rebuild it. Can anybody recommend a rebuild kit?