I can tell you that I had an intermittent Battery light just over a year (right after the warranty ran out) after replacing my alternator. I ignored it for a while, but eventually it died on the road with a dead battery. It turned out to be the connector at the alternator (part of the wiring harness -- not the alternator). I wound up replacing both connector and alternator(again). I wasn't absolutely sure that the alternator itself wasn't involved and my local Autozone was unable to bench test the old unit. I certainly didn't want to put a bad alternator back, given the difficulty of the task.
