Chrysler Repair: 2001 Chrysler T & C: battery light on, alternator pulley, c battery

Question
On Saturday I was going home from work and I noticed the battery light came on.  I stopped thinking the belt broke but it did not.  Then I started driving again and after maybe 1 or 2 minutes the light came on again and stay on until I got home.  I went to an auto part and tested the alternator and it was good.  Also, I let it run for about maybe a 1 or 1 1/2 and was still taking charge so tested the battery and it was not too good so I change the battery.  I drove the van for about 1 1/2 day and the light came on again.  What do you think it might be the problem?  I thought of changing the alternator what do you think?

Answer
Hi Yunior,
It probably is the alternator, but just in case you might want to check to be sure the serpentine belt is not too loose and therefor slipping on the alternator pulley. The control of the alternator by the computer could also be a problem or the wire that does that control. One thing to do first is a get a fault code readout for free at an Autozone parts store. Ask for the code number and the title of the code, then let me know what you learned and we can go from there.
Roland