Diagnostic Table
WARNING: This page is about a different car, the 2013 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
The following table is used to guide diagnosis of the refrigerant system if operating pressures are outside normal limits.
- Refer to the chart below.
High (Discharge) Pressure Low (Suction) Pressure Component - Causes High or Clutch Cycling High Condenser - inadequate airflow. High Normal to High Engine - overheating. Normal to High Normal Refrigerant overcharge - air in refrigerant. Normal to Low Normal to High A/C suction line - partially restricted or plugged. (1) Normal to Low Low or Clutch Cycling Low refrigerant charge, A/C suction line-partially restricted or plugged. (2) Erratic Operation or Compressor Not Running Evaporator discharge air temperature sensor or A/C pressure transducer - poor connection at A/C clutch connector. A/C electrical circuit erratic - see A/C Electric Circuit Wiring Diagram. Normal to Low High Compressor - low performance. Additional Possible Cause Components Associated With Inadequate Compressor Operation - Compressor drive belt - loose
- Compressor clutch - slipping
- Clutch coil open - shorted, or loose mounting
- HVAC module
- Clutch wiring circuit - high resistance, open or blown fuse
- Compressor operation interrupted by PCM
Additional Possible Cause Components Associated With a Damaged Compressor - Incorrect clutch air-gap
- Refrigerant leaks
(1) Low pressure reading will be normal to high if restriction is downstream of service access valve. (2) Low pressure reading will be low if restriction is upstream of service access valve.