Doesn't matter what car it came out of, it either works or it doesn't. You can put in a dc generator from a 49 Pontiac Torpedo Back if you wanted to and it would still charge the battery. Is the alternator the stock type with a regulator or an SI type with an internal regulator?
Like Sprint 6 says if the Alternator is good the next thing is check or replace the voltage regulator. If that is good also then maybe a fusible link. Have you been doing any other wire work under the hood? Was the 'GEN' light on when you bought the car?
