Grand Marquis V8-4.6L VIN W (1999)
Heater Air Plenum Chamber: Service and Repair
REMOVAL
1. Remove the rear seat airflow duct.
2. Remove the instrument panel.
3. Drain the coolant from the radiator so the coolant level is below the heater core.
4. Disconnect the heater water hoses.
5. Inside the vehicle, remove the nut.
6. Disconnect the vacuum hoses.
NOTE: Mark the locations of the vacuum hoses.