Glad you got to the bottom of your alternator problem. This story is a good illustration of how we can get tunnel vision and not realize that the problem that manifests itself can sometimes be the effect of another problem that's the root cause.
The first truck I got that had one continuous serpentine fan belt, the belt started squeaking, so I replaced it. Soon the new belt was squeaking, too. After a couple more replacements, I took the truck to a mechanic who checked all the pulleys and fixed one that didn't line up. Years later, no belt squeaking.