I owned a 95 Lumina back in the days and I had a similar problem. I had to bypass the ground in the alternator, most alternators have them, I re grounded it and it worked like a charm. The are referred as a test hole in the alternator.
But like I said above alternator whining is usually caused by bad bearings, a loose pulley, or the wrong size serpentine belt, normally due to a tight pulling of the pulley.