Alternator Problems

I have a 1997 Lincoln Continental. I have just replaced the Alternator for the third time in the last couple years. At least the last one was still under warranty. Any ideas why I am going through so many alternators. Is there something that could be checked that might be doing this. Anyone else having this problem?

I just replaced my alternator. . the car was basically running off of the battery. I took it to an Auto Electric mechanic in town and he found that the 1997 had 3 different alternators. The first one he got was the wrong one, and he finally got the right alternator. Have not had any problems with the charging system since he replaced the Alternator, Battery and Battery cable end.