Procedure 2 - Ambient Temperature Above 38°C (100°F)

1. Drive the vehicle or run the engine until it reaches normal operating temperature.
2. Connect a R-134a Manifold Gauge Set or R-134a Refrigerant Management Machine with high-pressure and low-pressure gauges to the refrigerant system.
3. Set the climate controls.
   • If equipped with manual climate control, set the A/C controls for normal A/C-PANEL mode, full COOL temperature, FRESH air, MED-LO blower. If the vehicle has a fresh air/recirc button, set it to FRESH. If the vehicle has an A/C switch or compressor on switch, set it to A/C ON.
   • If equipped with Electronic Automatic Temperature Control (EATC) or Dual Automatic Temperature Control (DATC), set temperature to 15°C (60°F) (lowest possible temp setting). Manually set blower to MED-LO (3 to 4 bars). If the vehicle has a fresh air/recirc button, set it to FRESH. If the vehicle has an A/C switch or compressor on switch, set it to A/C ON.
4. Open all vehicle windows and leave the hood open for the test. Open the rear hatch and/or rear doors (if equipped).
5. Confirm the compressor clutch is engaged and the engine cooling fan(s) are operating or engaged. Allow the vehicle to idle until the suction (low-side) and discharge (high-side) pressures are stable or fluctuate in a range that repeats.
6. Record the ambient (shop) temperature.
7. Record the discharge pressure. If the pressure is fluctuating, record the average value.
8. Determine if the discharge pressure falls within the normal operating limits using the Normal Refrigerant Discharge Pressures graph below.
   Fig 1: Normal Refrigerant Discharge Pressures Graph

   Courtesy of FORD MOTOR CO.
9. Record the suction pressure. If the pressure is fluctuating, record the average value.
10. Determine if the suction pressure falls between normal operating limits using the Normal Refrigerant Suction Pressures graph below.
    Fig 2: Normal Refrigerant Suction Pressures Graph

    Courtesy of FORD MOTOR CO.
11. Proceed to DIAGNOSTIC TABLE .

Diagnostic Table 

1. Refer to the table below.
   NOTE: The following table is used to guide diagnosis of the refrigerant system if operating pressures are outside normal limits.
   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	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) A/C evaporator discharge air temperature sensor - reading erratic or low (if equipped).
   Erratic Operation or Compressor Not Running		A/C evaporator discharge air temperature sensor - poor connection at A/C clutch connector or A/C evaporator discharge air temperature sensor connector. A/C electrical circuit erratic - see AIR CONDITIONING .
   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 Engine Computer
   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 pressure is taken near the compressor and restriction is upstream of service access valve.