Disclaimer: This information is for guidance only and does not constitute professional automotive advice. I am not responsible for any damage or injury resulting from attempting this repair.
General Procedure (High-Level):
1. Preparation: Disconnect the negative battery terminal. Gather your tools: screwdrivers (Phillips and flathead), sockets (various sizes), wrenches, pliers, a coolant drain pan, shop rags, possibly a sealant for reassembly, and potentially a heater core flush tool. You will likely need to acquire a new heater core. Obtain a service manual.
2. Drain Coolant: Drain the engine coolant completely. Locate the drain petcock on the engine block and the radiator drain valve. Have your drain pan ready.
3. Dashboard Disassembly: This is the most laborious part. You will need to partially or completely disassemble the dashboard to access the heater core. This involves removing:
* Steering Wheel: May need to be removed or at least significantly loosened to access other components.
* Steering Column: Might need partial disassembly.
* Instrument Panel: Unbolt and carefully remove. Be mindful of wiring harnesses and fragile plastic clips.
* Glove Box: Remove for better access.
* Center Console: Remove to access the heater core housing.
* Various Trim Pieces: Many small panels and trim pieces will need to be removed to expose the heater core. Take photos as you go to help with reassembly!
4. Heater Core Housing Access: Once the dashboard is sufficiently disassembled, you'll need to access the heater core housing, usually located behind the dashboard. This often involves removing various screws, bolts, and clips.
5. Disconnect Heater Core Hoses: Carefully disconnect the heater core hoses. Have rags ready to absorb coolant spillage. Mark the hoses to ensure correct reinstallation.
6. Remove Heater Core: The heater core is usually held in place by clips or screws within the housing. Remove it carefully. This can be tricky and often requires some maneuvering.
7. Install New Heater Core: Install the new heater core, ensuring it's properly seated.
8. Reconnect Heater Core Hoses: Reconnect the heater hoses, ensuring a tight seal.
9. Reassemble Dashboard: Carefully reassemble the dashboard, following the reverse order of disassembly. Pay close attention to all wiring harnesses and clips.
10. Refill Coolant System: Refill the engine coolant system with the correct type and amount of coolant. Bleed the air from the system thoroughly to prevent overheating.
11. Test: Start the engine and check for leaks. Test the heater to ensure it's functioning properly.
Crucial Considerations:
* Repair Manual: An official repair manual for your specific vehicle is absolutely essential. This will provide detailed diagrams and instructions, preventing costly mistakes.
* Patience: This is a lengthy and complex process. Be patient and methodical.
* Safety: Always disconnect the battery negative terminal before starting work to prevent accidental shorts. Wear safety glasses to protect your eyes.
* Professional Help: If you're uncomfortable with any aspect of this repair, consider seeking professional assistance from a qualified mechanic. The cost of professional repair may be less than the cost of damaging your vehicle.
This is a simplified overview. Without detailed diagrams and specific instructions for your 1996 Pontiac Grand Am SE, this procedure is insufficient. Again, strongly recommend consulting a service manual before attempting this repair.
