Charging issue!!

Maybe you didn't get the wires put back correctly on the starter solonoid. All of the wires should be on the stud closest to the firewall (except for the things it specifically says to change in the mini-starter instructions - be careful about those installs, I ruined a couple solonoids installing a mini-starter - my instructions were wrong, I beleive)

Anyway, make sure you got all the wires hooked back up and make sure the alternator wires aren't loose or falling apart.

I'm not positive, but maybe it could also have something to do w/ your voltage regulator, which is in the alternator on these cars and I beleive it can be checked at autozone.