I was driving home about 3 days ago, cruising about 55 MPH and my battery warning light flickerd. I drove home praying that id make it home as my lights would dim as the engine revved higher. I made it home and the car sat for a day. I took it out again the next day and my battery light was fully on (not dim and comming on and off) I just made it to the base of my driveway when the car stalled out and didnt have the power to crank the starter. I pushed it up my driveway and plopped another battery in (out of my 740) the engine cranked over but the battery light was on the whole time. so heres my problem: the alternator is only 3 months old and the battery is about 4. Im preaty sure neithern of these are the culprets but what else could it be? I am thinking that it may be the voltage regulator, but am not sure if its internal on my alternator, or somewhere else in my engine bay. I'm not real familar with my volvos yet so if you guys think thats whats wrong could you tell me where it may be? Or could it be something totally else?

thanks for any help!

-Nick