Charging system indicator light

I have a 1997 malibu. The battery light came on while i was driving. I read the book, and was wondering if this could mean that my battery is about dead?

Likely the battery or the alternator...
The lite in my 99 Malibu comes on intermittently . I checked the battery and the alternator... I even replaced the alt. with a new one... lite still comes on...

So I'd love to hear too what else it could be...

It's the alternator. I had this on my 97 Malibu as did many other people. Don't take it to the dealer though. They charged me $450 for a repair, that if I would have done it myself would have been less than $100 and only about 2 hrs of my time.

Jeremy

Then how do you explain the fact that I just replaced my alternator (less than a year old) with a newly re-built one and the lite still comes on (intermittently)? Just another bad alt.?
There must be, at least in some cases, a different culprit... and as I said in my first post, the battery is in good shape...

Does anybody know which unit sends the signal to that lite? Is it hooked up to the battery and reads the charge voltage directly or, is it the ECU reading that voltage and, if too low, activates the lite? A different setup altogether?