Diagnostic Table
WARNING: This page is about a different car, the 2007 Mercury Mariner and 2007 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
- Proceed to the diagnostic table.
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 High Fixed orifice tube - missing O-rings leaking/missing Normal to Low Normal to high A/C suction line - partially restricted or pluggeda Normal to Low Low or clutch cycling Low refrigerant charge, A/C suction line - partially restricted or pluggedb A/C cycling switch - sticking closed Erratic Operation or Compressor not Running A/C cycling switch - poor connection at the A/C clutch connector or clutch cycling switch connector. A/C electrical circuit erratic - see the A/C Electrical 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
- Control Assembly Switch - dirty contacts or sticking open
- Clutch Wiring Circuit - high resistance, open or blown fuse
- Compressor Operation Interrupted by the PCM
Additional Possible Cause Components Associated With a Damaged Compressor - Incorrect Clutch Air-Gap
- Suction Accumulator - refrigerant oil bleed hose plugged
- Refrigerant Leaks
a Low pressure reading will be normal to high if the pressure is taken at the accumulator and if the restriction is downstream of the access valve.
b Low pressure reading will be low if the pressure is taken near the compressor and the restriction is upstream of the access valve
NOTE:
The following table is used to guide diagnosis of the refrigerant system if the operating pressures are outside the normal limits.