Tools You'll Likely Need:
* Socket wrench set (metric)
* Wrenches (metric)
* Ratchet and extensions
* Pliers
* Screwdrivers (Phillips and flathead)
* Battery terminal cleaner
* New alternator (ensure it's the correct one for your Trans Am)
* Jack and jack stands (crucial for safety!)
* Possibly a pulley puller (depending on the alternator design)
General Steps (Consult your repair manual for precise details and diagrams):
1. Safety First: Disconnect the negative (-) battery terminal. This is crucial to prevent electrical shorts and injury.
2. Access the Alternator: The alternator's location varies slightly depending on the engine (3.0L V6 or 5.0L/5.7L V8). Generally, it's located on the engine's front, often near the power steering pump and/or water pump. You may need to remove some components to get better access, such as the air intake components or possibly the fan shroud. This is where a repair manual's diagrams are invaluable.
3. Disconnect Electrical Connections: Carefully disconnect the alternator's wiring harness connectors. Take pictures or make notes to remember which wire goes where. You'll likely have at least two connectors: one for the main power output and another for the exciter wire (smaller gauge).
4. Remove the Alternator Mounting Bolts: Locate the alternator mounting bolts. These are typically two or three bolts. Carefully remove them, keeping track of any washers or spacers.
5. Remove the Alternator: Once the bolts are removed, the alternator should come loose. However, it might be slightly tight due to the belt tension. You may need to slightly loosen the alternator belt tensioner to remove it easier. Again, your repair manual will show you how to do this safely and effectively.
6. Install the New Alternator: Carefully install the new alternator, ensuring it's correctly aligned with the mounting points. Reinstall the bolts, tightening them to the manufacturer's specified torque. Do not overtighten!
7. Reconnect Electrical Connections: Reconnect the wiring harness connectors, making sure they are securely attached.
8. Reconnect the Belt: Carefully route the serpentine belt back onto the alternator and all other pulleys. Ensure the belt is properly seated on all the pulleys and the tension is correct. A belt tension gauge might be helpful here, but you can often rely on the feel of the belt's tension—it should be snug but not overly tight.
9. Reconnect the Battery: Reconnect the negative (-) battery terminal.
10. Test the Alternator: Start the engine and check the alternator output voltage using a multimeter. The voltage should be around 13.5-14.5 volts. If it's not, there might be a problem with the new alternator, the wiring, or the charging system.
Important Considerations:
* Serpentine Belt: You may need to replace the serpentine belt if it's worn or damaged.
* Pulley Removal: Some alternators have pulleys that need to be removed and reinstalled separately—this usually requires a pulley puller.
* Repair Manual: Investing in a Haynes or Chilton repair manual specific to your 1987 Pontiac Trans Am is strongly recommended. The diagrams and torque specifications are invaluable.
This is a general guide. Without specific knowledge of your car's engine and the exact alternator model, providing detailed instructions is impossible. Always prioritize safety and consult a repair manual for accurate and detailed steps. If you're uncomfortable performing this repair yourself, taking it to a qualified mechanic is always the safest option.
