Replacing the alternator in your 2001 Buick Century is a good project to do yourself. It can save you from paying a large repair bill to a garage or the dealership’s service department for a relatively simply job. The alternator on the 3.1-liter engine in this car sits on top of the right-hand cylinder head as you look at the engine. Accessibility is very good and you can remove and replace the alternator with basic hand tools in about and hour.
Locate the negative battery terminal, then remove the retaining bolt holding the negative battery cable in place, using a wrench. Remove the cable from the battery and set it aside.
Move to the passenger-side fender so you are facing the front of the engine. Locate the serpentine belt tensioner on the engine and place a socket and breaker bar on the bolt in the center of the pulley. Rotate the tensioner counterclockwise to relieve the tension on the belt, then slide the belt off the alternator pulley.