How do you change heater core on 2004 Pontiac Grand Am?
Disconnect the negative battery cable............................
- Drain the cooling system into a clean container for reuse.
- Raise and safely support the vehicle.
- Remove the drain tube from the heater housing.
- Disconnect the heater hoses from the heater core.
- Lower the vehicle.
- Remove or disconnect the following:
Console, if equipped Sound insulators from both sides Steering column opening filler Air outlet duct Rear floor air outlet screws and the outlet Heater core cover Heater core-to-housing mounting clamps and the heater core