Test I: Incorrect/Erratic Direction of Airflow From Outlet(s) - DATC

PINPOINT TEST I: INCORRECT/ERRATIC DIRECTION OF AIRFLOW FROM OUTLET(S) - DATC

I1-I3:

I4-I6:

I7-I9:

I9-I11:

I11-I14:

I14-I16:

I16-I17:

I18-I19:

Normal Operation
Under normal operation, the automatic temperature control (ATC) solenoid and manifold receives a ground from the dual automatic temperature control (DATC) module through circuit 1070 (BN/LB). Depending on which solenoid is to be energized, the ATC solenoid and manifold receives power from the DATC module through circuits:
- 1501 (BK) for the air inlet door vacuum control motor.
- 1502 (BK/YE) for the defrost door vacuum control motor.
- 1503 (BK/LB) for the floor door vacuum control motor.
- 1504 (RD/WH) for the panel door vacuum control motor.
- 1069 (OG/LB) for the heater control valve.

Engine vacuum is supplied to the ATC solenoid and manifold. When one of the solenoids is energized, vacuum is applied to the control motor or valve and the desired door or valve is either opened or closed.

Possible Causes
- An open, short to voltage, ground or together in circuits 1501 (BK), 1502 (BK/YE), 1503 (BK/LB), 1504 (RD/WH) or 1069 (OG/LB).
- ATC solenoid and manifold.
- DATC module.
- Heater control valve.
- Vacuum control motor.
- Stuck or bound linkage or door.
- Leaking or plugged vacuum hose.