About a week ago I noticed the volt meter showing 12 volts. After parking the car for a few hours I started the car and it went back to roughly 14 volts. During last week I noticed 12 volts a few more times and now it seems to sit between 12.5 to 13v.

So I went by Auto Zone today to have them test it. They hooked up their tester and basically read voltage. Don't think it put any load on anything. With the car off, they read roughly 12.6 volts and said the battery was 100% charged. With the car running, I think when we first started it it read something like14.6 and then came down to 14.4 to 14.2.

So based on these readings it looks to me like the alternator is fine. Plus I haven't noticed any dimming or other issues. So now I'm wondering if there is something off with the gauge. Couple of questions:

1. Is this a common or uncommon issue?
2. If there is a bad part, what is it and where is it? Is it the gauge or is there a sending unit or what?

Thanks!
Mike