Tools You'll Likely Need:
* Wrench Set (Metric): Various sizes, including those appropriate for your alternator's mounting bolts and the battery terminals.
* Socket Set (Metric): Similar size range as the wrench set.
* Ratchet: To use with sockets.
* Pliers: For disconnecting battery terminals.
* Screwdriver (Phillips and/or Flathead): Depending on the alternator's mounting system.
* Jack and Jack Stands: Crucial for safety. Never work under a car supported only by a jack.
* Wheel Chocks: To prevent the car from rolling.
* Battery Terminal Cleaner: Recommended for cleaning connections after the job.
* New Alternator: Make sure you get the correct replacement alternator for your specific engine.
* Gloves and Safety Glasses: Always protect yourself.
Steps (General Outline):
1. Disconnect the Battery: This is the most important step to prevent electrical shorts and injury. Disconnect the negative (-) terminal first, then the positive (+) terminal.
2. Prepare the Vehicle: Park on a level surface, engage the parking brake, and use wheel chocks. Raise the front of the vehicle using a jack and securely support it with jack stands.
3. Access the Alternator: The alternator's location varies slightly depending on the engine (V6 or V8). You'll likely need to remove some components to access it. This might include:
* Air Cleaner Assembly: Often needs to be removed or moved out of the way.
* Serpentine Belt: You'll almost certainly need to remove the serpentine belt. Consult a diagram to determine the correct routing when reinstalling it. Use a belt tensioner tool (or a proper method described in your repair manual) to release the tension on the belt.
* Other Components: Depending on your Firebird's configuration, additional components might need to be partially removed for better access.
4. Disconnect Electrical Connections: Disconnect the alternator's wiring harness connector(s). Take pictures or make notes of the connections before disconnecting to ensure correct reassembly.
5. Remove the Alternator Mounting Bolts: Locate and carefully remove the bolts securing the alternator to the engine.
6. Remove the Alternator: Once the bolts are removed, carefully remove the alternator. It may be somewhat heavy.
7. Install the New Alternator: Carefully install the new alternator, making sure it's correctly aligned with its mounting points. Secure it with the mounting bolts.
8. Reconnect Electrical Connections: Reconnect the alternator's wiring harness connector(s), matching the connections to your previous notes or photos.
9. Reinstall Components: Reinstall any components you removed to access the alternator (serpentine belt, air cleaner assembly, etc.), ensuring everything is properly connected and secured.
10. Reconnect the Battery: Reconnect the battery terminals, positive (+) first, then negative (-).
11. Check Operation: Start the engine and verify that the alternator is charging the battery. You may want to use a multimeter to check the voltage output.
Important Considerations:
* Serpentine Belt Routing: Incorrect routing can damage the belt and other components. Refer to your repair manual for the correct routing diagram.
* Torque Specifications: Use the correct torque specifications for all bolts to prevent damage.
* Safety First: Always prioritize safety. Never work under a vehicle supported only by a jack. Use jack stands and wheel chocks. Disconnect the battery before starting work.
This is a general guide. Consult a repair manual specific to your 1999 Pontiac Firebird and its engine for detailed, accurate instructions and torque specifications. If you are not comfortable performing this repair yourself, it's best to take it to a qualified mechanic.
