Dodge Repair: Charging system light on, alternator brushes, dash light

Question
1999 stratus, DOHC, 153,000 miles. The dash charging system light is on in the dash. Removed alternator and had it checked. Alternator brushes were 90% worn so I had it rebuilt. Dash light still on. Tested battery showed 9.1 volts and would not hold a charge. Replaced battery. Light still on. What am I missing here? Yes the belt is tight, 1/2" deflection in it.

Answer
have some one scan the cars computer and get the code that is coming up.  And fyi  I doubt the alt brushes were worn. In all my years and most of every other Chrysler's tech years  they vary rarely go bad  ever. Check the alt fuse  or fuse link  and wires from the PCM to the Alt  make sure u have 12 volts there and so on.