Explorer 2WD V6-245 4.0L (1994)
Vacuum Check Valve HVAC: All Technical Service Bulletins
Heater - Air Flow With System in the Off Mode
Article No.
95-6-14
03/27/95
HEATER - OBJECTIONABLE AIRFLOW FROM PANEL REGISTERS DURING HEAVY ACCELERATION - NON-A/C VEHICLES
LIGHT TRUCK:
1993-94 EXPLORER, RANGER
ISSUE:
Objectionable airflow from the heater system panel registers may occur when the system is in the OFF mode and the vehicle is under heavy acceleration.
This condition is caused by movement of the fresh air door when the vacuum to the door actuator is lost during heavy acceleration or other low engine
vacuum conditions.
ACTION:
Installation of a vacuum hose/reservoir/check valve assembly will provide sufficient vacuum level to maintain the heater system fresh air door in the
closed position. Refer to the following procedure for service details.
SERVICE PROCEDURE
1.
Remove the blower assembly from the vehicle.
2.
Drill two (2) holes in the blower assembly, in a vertical position, to allow for installation of the vacuum reservoir. Refer to Figure 1.
3.
Using two (2) screws (389915-S2), mount the vacuum reservoir (F4Tz-19A566-A) as shown in Figure 1.
4.
Disconnect the existing vacuum check valve from the engine vacuum harness and the main wiring harness.
5.
Reinstall the blower assembly in the vehicle.
6.
Attach the vacuum hose in the wire harness to the new check valve included with the vacuum reservoir.
7.
Remove the inline connector to the "T" in the engine vacuum harness.
8.
Attach the check valve to the engine vacuum harness with the vacuum hose and inline connector provided on the assembly.
9.
Start the engine and verify proper operation of the Fresh Air/Off door.
