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.
Locate the wiring harness connector on the back of the alternator. Depress the locking tab on the connector and pull it free from the alternator. Lay it aside, then find the battery connection on the back of the alternator. Remove the locking nut from the terminal with a wrench and pull the wire off the terminal.
Locate the retaining bolt on the top of the alternator and remove it with a socket and ratchet. Find the second bolt at the bottom of the alternator, on the front of the unit. Remove it with a socket and ratchet, then lift the alternator off the engine and out of the engine compartment.
Set a new alternator in place on the engine and install the upper and lower retaining bolts. Torque the bolts to 37 ft-lbs. with a torque wrench and socket.
Plug the wiring harness connector into the back of the new alternator, making sure it locks in place. Slide the battery output wire onto the BAT terminal, followed by the retaining nut. Torque the retaining nut to 15 ft-lbs. with a torque wrench and socket.
Rotate the serpentine belt tensioner counterclockwise, then slide the belt onto the new alternator. Rotate the tensioner back to the home position and remove the breaker bar and socket from the assembly.
Install the negative battery cable end onto the negative battery terminal. Install the retaining bolt and tighten it with a wrench.
