Intermittent Charging Alternator; 97 Explorer

97 Explorer. 4.0L. Automatic. 2WD.

Voltage at battery either 14.1 volts or 12.2 as measured with volt meter. A gentle tap on the alternator usually restores the 14 volt reading. No loose wires.

Are the brushes a potential culprit here? If so, are they easily obtained and replaced ?

If it's not the brushes, is there any other repairable part (regulator?) on these alternators that could cause the problem?

Thanks.

I think on these alternators everything is internal. If you look at the back of it and see a gray or black square with 4 little screws in it, the regulator is replaceable. If the back is solid, or the wiring connection is inside the case, replace alternator.