Tools You'll Need:
* Wrench set (metric): You'll need various sizes, likely including 10mm, 13mm, and possibly larger.
* Socket set (metric): Similar sizes to the wrench set, plus potentially a ratchet and extensions for better access.
* Screwdrivers: Both Phillips and flathead.
* Pliers: Needle-nose pliers might be helpful.
* Jack and jack stands: Essential for safely lifting the vehicle.
* Wheel chocks: For safety.
* New alternator: Make sure you get the correct one for your Lumina's engine.
* Battery terminal cleaner: Recommended.
* Gloves and safety glasses: Always protect yourself.
* Optional: Torque wrench: For accurate tightening of bolts.
Steps:
1. Disconnect the Battery: This is the *most* crucial step. Disconnect the negative (-) terminal first, then the positive (+) terminal. This prevents accidental shorts and shocks.
2. Prepare the Vehicle: Park on a level surface, engage the parking brake, and use wheel chocks. Raise the front of the vehicle using the jack and secure it safely on jack stands.
3. Locate the Alternator: The alternator is usually located on the front of the engine, driven by a belt. Its location might vary slightly depending on the engine type.
4. Remove the Belts: Use a belt wrench or a suitable tool to loosen the alternator's belt tensioner. This allows you to remove the serpentine belt from the alternator pulley. *Take a picture or make a diagram of the belt routing before removing it to ensure correct reinstallation.*
5. Disconnect Electrical Connections: There will be at least two electrical connectors attached to the alternator. Carefully disconnect these. Sometimes a retaining clip needs to be released first.
6. Remove the Alternator Mounting Bolts: Usually, there are two or three bolts holding the alternator in place. Carefully remove these bolts.
7. Remove the Alternator: Once the bolts are removed, carefully remove the alternator from its mounting bracket. It might be heavy, so be prepared.
8. Installation (Reverse Order):
* Install the new alternator onto the mounting bracket.
* Secure it with the mounting bolts, tightening them to the proper torque specification (check your repair manual).
* Reconnect the electrical connectors.
* Reinstall the serpentine belt, following your diagram or picture.
* Tighten the belt tensioner.
* Lower the vehicle.
* Reconnect the battery terminals (positive first).
Important Considerations:
* Belt Tension: Ensure the serpentine belt is properly tensioned after reinstallation. Too loose, and it will slip; too tight, and it will put stress on the bearings.
* Torque Specifications: Always use the correct torque specifications for all bolts from your repair manual. Over-tightening can damage components.
* Charging System Test: After installation, it's a good idea to have your charging system tested at an auto parts store to ensure the new alternator is functioning correctly.
This is a general guide. Consult a repair manual specific to your 1990 Chevy Lumina for detailed instructions and diagrams tailored to your vehicle's engine. If you are uncomfortable performing this repair, it's best to take your vehicle to a qualified mechanic. Working on a car can be dangerous if you're not familiar with the procedures.
