Electrical problem

I have a 1999 tracker. I have installed a new battery and the alternator is 1 year old. The other day the battery died so I put a new one in. Now the battery light is on when the vechicle is at idle. When I give it some gas it goes out. It also seams to die when I come to a stop but starts right back up. I tested the alt with a voltage meter and it is charging. Could it be the voltage regulator? Where is it and how do I check it? Thanks

Pull your alternator Advance checks them for free. The regulator is on the alternator.