im going to assume your accessories work on this one. check the connection of the two lines from the alternator to your battery. im sure one is broken. ive never heard of an alternator going, hell ive seen ones directly out of 1980's junk cars do fine on a testor. im thinking its going to be the line to or from the alternator. the lines are hard to follow. see if you can get your hands on the haynes repair manual and try replacing the wire first. if that doesnt fix it then try a new battery or another battery out of another car. last resort if i was you would be to pull the alternator (very hard to get to, prolly have to go from underneath the car) and have it checked or replaced