Umm pulleys almost never make any noise, so replacing the pulley isn’t likely going to solve anything. Or maybe you know something you’re not saying? Like it was damaged at some point in the past, or maybe you have an alignment problem caused by damage or poor prior maintenance.
Most likely the bearings are going out in the alternator or the belt isn’t under proper tension “sqeaking” as it rounds the alternator. FYI replacing the tensioner pulley is not the same thing as replacing the tensioner assembly
