W/Harness Inspection

Air Conditioner

B1279 Air Mix Switch Potentiometer Open (Low)-Console - W/Harness Inspection

Terminal and Connector Inspection

1. Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?






Signal Circuit Inspection

Check for open in harness
1. Ignition "OFF"
2. Disconnect Console temperature actuator & Switch and A/C control unit main harness connector.
3. Measure resistance between Signal (F/B) terminal of Console temperature actuator & Switch harness connector and Signal (F/B) terminal of A/C-ECU harness connector.

Specification : 1 Ohms below




4. Is the measured resistance within specification?





Check short to ground in harness
1. Ignition "OFF"
2. Disconnect Console temperature actuator & Switch and A/C control unit main harness connector.
3. Measure resistance between Signal (F/B) terminal of Console temperature actuator & Switch harness connector and chassis ground.

Specification : Infinity




4. Is the measured resistance within specification?






Power Circuit Inspection

Check power in harness
1. Ignition "OFF"
2. Disconnect Console temperature actuator & Switch and Connect A/C control unit main harness connector.
3. Ignition "ON"
4. Measure voltage between Sensor REF (5 V) terminal of Console temperature actuator & Switch harness connector and chassis ground.

Specification : approx. 5 V




5. Is the measured voltage within specification?