My charging light has been glowing for a couple of weeks, mostly at idle but it seems to be more persistent at rpms up to 2000. Light goes at out above that. Measured voltage at the battery and have 12.5v at the lower rpms. I revved it up and saw an increase - up to around 13.5v but readings were intermittent. When this started to occur i would see 14.6v for anything above idle speed. All connections and grounds have been checked and cleaned. Auto parts store checked the alternator and said it checked out OK. They said they can't isolate particular conditions? Stock reman. alternator and regulator have 60,000 miles. Bad brushes in alternator? Any other checks to do?
Thanks,