Test B: Incorrect/Erratic Direction Of Airflow From Outlet(s)
PINPOINT TEST B: INCORRECT/ERRATIC DIRECTION OF AIRFLOW FROM OUTLET(S)Normal Operation
Under normal operation, to rotate the mode door actuator clockwise, the HVAC module supplies voltage to the BLEND, DEFROST and FLOOR/PANEL mode door actuator motors through the door actuator feed B circuits, and supplies ground through the door actuator feed A circuits. To rotate the mode door actuator counterclockwise, the HVAC module reverses the voltage and ground circuits.
The mode door actuator feedback resistors are supplied a ground from the HVAC module by the mode door actuator return circuits and a 5-volt reference voltage on the mode door actuator reference circuits. The HVAC module reads the voltage on the mode door actuator feedback circuits to determine the mode door actuator position by the position of the actuator feedback resistor wiper arm.
Door actuator feed B circuits
- Blend - 1376 (BK/LB)
- Defrost - 1137 (YE/LG)
- Floor/Panel - 1129 (BN/WH)
Door actuator feed A circuits
- Blend - 1375 (PK/YE)
- Defrost - 1136 (RD/WH)
- Floor/Panel - 1128 (GY/LB)
Door actuator return circuits
- Blend - 438 (RD/WH)
- Defrost - 438 (RD/WH)
- Floor/Panel - 438 (RD/WH)
Door actuator reference circuits
- Blend - 436 (RD/LG)
- Defrost - 436 (RD/LG)
- Floor/Panel - 436 (RD/LG)
Door actuator feedback circuits
- Blend - 437 (YE/LG)
- Defrost - 1982 (LB/BK)
- Floor/Panel - 435 (YE/LB)
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Blend, air inlet, defrost and floor/panel mode door actuator motor
- HVAC module
- Stuck or bound linkage or door
B1-B2:
B3-B5:
B5-B7:
B7-B9:
B9-B11:
B11-B13:
B13 Continued:
B14-B15:
B15 Continued:
B16-B17:
B17-B18:
B18 Continued:
