the light on your dash has nothing to do with the charge going to your battery..
You are overdriving your alternator, purposefully, by any chance are you? (if you don't know what that means, then don't bother asking, as you probably aren't....)
Only thing that I can think of to be repetitive would be the belt causing failures (overdriven, etc) or liquid getting within the alt while being used.... Check for coolant leaks from the resevoir...
Ray
