2004 Chevrolet Malibu

Computer problem
2004 Chevy Malibu 6 cyl Two Wheel Drive Automatic 110078 miles

When I accelerate the battery light comes on for about 5 seconds then it goes off and doesn't come back on.I've replaced the battery and it still does this.I've also had it to a GM garage and they put it on the computer machine and it doesn't show any read outs about this issue. What do you think the problem is? Is it something to be concerned about?
August 9, 2009.

Did they check the alternator? Here is a how to if you want to try it yourself: