Pinpoint Test X: The Temperature Control Is Inoperative Using The Front Auxiliary Climate Controls
- X1 CHECK VOLTAGE TO BLEND DOOR ACTUATOR
- Disconnect: Auxiliary Temperature Blend Door Actuator C3004.
- Key in ON position.
- Measure the voltage between auxiliary temperature blend door actuator C3004-7, circuit 294 (WH/LB) and ground.
- Is the voltage greater than 10 volts?
Yes: GO to X2.
No: VERIFY the central junction box (CJB) fuse 18 (10A) is OK. If OK, REPAIR circuit 294 (WH/LB) for an open. TEST the system for normal operation.
- X2 CHECK THE BLEND DOOR ACTUATOR GROUND CIRCUIT
- Key in OFF position.
- Measure the resistance between front auxiliary climate control assembly C989b-9, circuit 57 (BK) and ground.
- Is the resistance less than 5 ohms?
Yes: GO to X3.
No: REPAIR circuit 57 (BK) for an open. TEST the system for normal operation.
- X3 CHECK THE TEMPERATURE BLEND DOOR ACTUATOR SIGNAL
- Key in ON position.
- Place the front auxiliary blower motor switch in HI.
- Measure the voltage between auxiliary temperature blend door actuator C3004-3, circuit 1126 (LB) and ground. Rotate the temperature control switch to full COOL then to full WARM.
- Does the voltage vary from greater than 10 volts (full COOL) to less than 1 volt (full WARM)?
Yes: INSTALL a new auxiliary temperature blend door actuator. TEST the system for normal operation.
No: GO to X4.
- X4 CHECK CIRCUIT 1126 (LB) FOR AN OPEN
- Key in OFF position.
- Disconnect: Front Auxiliary Climate Control Assembly C989b.
- Measure the resistance between front auxiliary climate control assembly C989b-3, circuit 1126 (LB) and auxiliary temperature blend door actuator C3004-3, circuit 1126 (LB).
- Is the resistance less than 5 ohms?
Yes: INSTALL a new front auxiliary climate control assembly. TEST the system for normal operation.
No: REPAIR circuit 1126 (LB) for an open. TEST the system for normal operation.