Refrigerant System Tests

Courtesy of FORD MOTOR COMPANY	R-134A Side Wheel Manifold with Hoses 023-00047300-ROB40134AE
Courtesy of FORD MOTOR COMPANY	R134A REFRIGERANT RECOVERY RECYCLING And RECHARGE MA (R-134a Refrigerant Management Machine (SAE Compliant)) 300-ROB34288
Courtesy of FORD MOTOR COMPANY	A/C SERVICE MACHINE PRINTER 199-00067

Ambient Temperature at or Below 38°C (100°F) 

1. 1.
   
   Drive the vehicle or run the engine until it reaches normal operating temperature.

1. 2.
   
   Connect a 023-00047 300-ROB40134AE, 199-00067 or 300-ROB34288 to the refrigerant system.

1. 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, HI 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 EATC, set temperature to 15°C (59°F) (lowest possible temp setting) with the dual function disabled (if equipped). Manually set blower on HI. 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.

1. 4.
   
   Open all vehicle windows and leave the hood open for the test. Open the rear doors.

1. 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.

1. 6.
   
   Record the ambient (shop) temperature.

1. 7.
   
   Record the discharge pressure. If the pressure is fluctuating, record the average value.

1. 8.
   
   Determine if the discharge pressure falls within the normal operating limits using the Normal Refrigerant Discharge Pressures chart in illustration.

Courtesy of FORD MOTOR COMPANY

1. 9.
   
   Record the suction pressure. If the pressure is fluctuating, record the average value.

1. 10.
   
   Determine if the suction pressure falls between normal operating limits using the Normal Refrigerant Suction Pressures chart in illustration.

Courtesy of FORD MOTOR COMPANY

1. 11.
   
   Proceed to the Diagnostic Table below.

Ambient Temperature Above 38°C (100°F) 

1. 1.
   
   Drive the vehicle or run the engine until it reaches normal operating temperature.

1. 2.
   
   Connect a 023-00047 300-ROB40134AE, 199-00067 or 300-ROB34288 to the refrigerant system.

1. 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 EATC, set temperature to 15°C (59°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.

1. 4.
   
   Open all vehicle windows and leave the hood open for the test. Open the rear hatch and/or rear doors (if equipped).

1. 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.

1. 6.
   
   Record the ambient (shop) temperature.

1. 7.
   
   Record the discharge pressure. If the pressure is fluctuating, record the average value.

1. 8.
   
   Determine if the discharge pressure falls within the normal operating limits using the Normal Refrigerant Discharge Pressures chart in illustration.

Courtesy of FORD MOTOR COMPANY

1. 9.
   
   Record the suction pressure. If the pressure is fluctuating, record the average value.

1. 10.
   
   Determine if the suction pressure falls between normal operating limits using the Normal Refrigerant Suction Pressures chart in illustration.

Courtesy of FORD MOTOR COMPANY

1. 11.
   
   Proceed to the Diagnostic Table below.

Diagnostic Table 

1. 1.
   
   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 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 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.