noise in stereo
The noise in your stereo (a whining that increases or decreases with RPMS...I'm betting...right?) is feedback you're getting from the alternator. That noise alone may not mean your alternator is bad, but that you might need to run a heavier ground from your stereo system to get rid of the annoying sound. Did you recently install an aftermarket amp or some sort of equalizer? Is it worse when the headlights are on at night? That'll give you that alternator whine from time to time if it is not heavily grounded. Been there.
As far as sounds from the alternator itself, a grinding or "noisy belt" like sound can mean that the bearings are going bad. I know, its hard to isolate the exact sound...I thought I had a worn belt when the alternator bearings were rotting away on my 91 Ranger, but it turned out to be the alternator...not the belt.
Another sign that the alternator is going is when you're driving along and you notice wild fluctuations in the volt/amp gauge on your dash. It may not happen all the time, but it will get worse over time.
Take my advice...I've been there DO NOT buy ANY rebuilt alternators. They're nothing but trouble and don't last very long as a rule. This also goes for rebuilt power steering pumps and water pumps too.
If you plan on keeping your vehicle for any length of time, spend the extra money and put a new unit in. When you konk out in the middle of the night or in the middle of nowhere, due to cutting corners on a rebuilt part, you'll wish like hell you'd spent the extra money (been there too!).
good luck,
-SA
