Usually when the alternator fails for the first time it is almost always because of worn brushes housed within the regulator body which is mounted by two screws to the backside of the alternator.

It takes 5 minutes to remove and replace the regulator....Very simple to do! They cost about $50........

Why are you replacing the whole alternator? About the only thing that usually fails with the alternator is a lot of miles that eventually ware bearings out! If unless you have shorted the alternator and burned up the windings, or have worn bearings, you need only to replace the regulator and usually can be done without removing the alternator.

VolvoSavvy........