Over Charging Issues

I don't believe that is the issue. Yeh, I know, he says he wiggled it and it went away, but I do not believe that is the cause. I've posted a LOT about these problems. A loose connection(s) in the field circuit should cause UNDER voltage if anything.

Rarely, a bad battery will cause overcharge, probably related to sulfation, etc

USUALLY this is caused by one of two things, either 1....voltage drop in the ground circuit AKA the VR MUST be at the same V as the NEG battery terminal, and

2....V drop in the hot circuit which is way more common. Drop in the bulkhead connector, ignition switch connector and switch, and right at the ammeter. Bad connections right at the VR connector where power feeds the VR

A bad regulator can do this, but somewhat rare. Mostly, VRs fail or not, rather than "off voltage," but they can sometimes.