Test Q: The Auxiliary Temperature Control Only Is Inoperative/Does Not Operate Correctly

PINPOINT TEST Q: THE AUXILIARY TEMPERATURE CONTROL ONLY IS INOPERATIVE/DOES NOT OPERATE CORRECTLY

Q1-Q2:

Q2-Q4:

Q4-Q6:

Q7-Q9:

Q9-Q11:

Q11 Continued:

Normal Operation
Under normal operation, to rotate the auxiliary temperature blend door actuator clockwise, the SJB supplies voltage to the auxiliary temperature blend door actuator motors through the circuit 1375 (PK/YE), and supplies ground through circuit 1376 (BK/LB). To rotate the auxiliary temperature blend door actuator counterclockwise, the SJB reverses the voltage and ground circuits.

The auxiliary temperature blend door actuator feedback resistor is supplied a ground from the SJB through circuit 1382 (BK/OG) and a 5-volt reference voltage on circuit 1381 (WH/LB). The SJB reads the voltage on the auxiliary temperature blend door actuator feedback circuit 1126 (LB) to determine the auxiliary temperature blend door actuator position by the position of the actuator feedback resistor wiper arm.

Possible Causes
- An open in circuit 1381 (WH/LB), 1375 (PK/YE), 1376 (BK/LB) or 1126 (LB).
- A short to ground circuit 1381 (WH/LB), 1375 (PK/YE), 1376 (BK/LB) or 1126 (LB).
- A short to voltage circuit 1381 (WH/LB), 1375 (PK/YE), 1376 (BK/LB) or 1126 (LB).
- A short together circuits 1375 (PK/YE) and 1376 (BK/LB) or 1126 (LB) and 1381 (WH/LB).
- Auxiliary temperature blend door actuator.
- SJB.