Happens in the mornings "mostly". I'm stopped at a light and the voltmeter will spike real quick. i.e. 13v-10v-13v. I don't hear anything kick on. Also, the battery is not staying charged where it used too, mid-line, now it's half way between midline and the red zone. The alternator is 10 years old, so I'm thinking it's going, I'm also hearing a spinning noise in that general area, I've never heard before. I don't really trust the "professionals" at the chain stores to touch my car, what do you think? Thanks.

 

That happens when the bass hits with my subs

If you're not listening to loud music, and nothing else is on, the alternator is probably going out

 

Thanks, That's what I was thinking. Where is a good place to buy a GM (non-rebuilt) alternator?

 

Its hard to find a non-rebuilt alt..... Just so you know, AC Delco only has a one year warranty....