I'm looking for a little advice on an electrical issue I am having with my 98 GT.

For the last week my battery light has been coming on when I start my car up. This usually goes away when I shift into drive. A few days ago I noticed that the amount of air being put through the vent kept fluctuating as I was driving.

I figured it was the battery or alternator going bad....normally I would check this myself but seeing as how its 20degrees out and I dont have a garage, I really didn't feel like messing with taking the alternator out to get it checked at autozone.

I dropped it off at the car shop to get it checked out. They said the battery and alternator check out fine but they would not rule out a bad battery cell or that the alternator was starting to go bad. I took it on a drive tonight to check it out, battery light popped on at start up and when off as I shifted into gear, dash lights were a little dim and heat was not blowing at full strength.

Any suggestions or ideas would be helpful.

Thanks,
Alex