Ford Mustang (1999-2004) Service Manual: Air Conditioning (A/C) System Check - Retail Procedure

NOTE: This Retail Procedure is not eligible for claiming on Ford paid repairs (warranty and ESP).

NOTE: The engine should be run at idle for 10 minutes with the air conditioning on and set to MAX A/C before carrying out this retail procedure.

NOTE: Read and follow all of the Warnings, Cautions and Notes at the beginning of this section before continuing.

1. Visual inspection

Open the hood and visually inspect the heating and air conditioning systems for the following:

  • Coolant reservoir for correct coolant level
  • Heater hoses for deterioration or loose connections
  • Radiator and condenser for debris or damaged fins restricting airflow, loose mounting or connections
  • Accessory drive belt(s) and cooling fan(s) for wear or physical damage
  • Refrigerant lines and connections for physical damage or loose connections
  • Compressor for physical damage or loose connections
  • Suction accumulator/drier for physical damage or loose connections
  • Wiring and connectors for excessive wear, loose or damaged connections, or incorrect routing

2. A/C refrigerant analysis

  • Carry out air conditioning refrigerant analysis. For additional information, refer to Refrigerant Identification Testing in this section.
  • If the refrigerant fails the analysis, discontinue diagnosis and make recommendations for repairs.
  • If the refrigerant passes the analysis, carry out the air conditioning system check.

3. Air conditioning system check

  • Connect manifold gauge set or charging station with gauges to refrigerant system.
  • With the vehicle in park, parking brake set, thermometer installed in center panel vent, and air conditioning system on and set to MAX A/C, start the engine.
  • Record air refrigerant system pressures while running the engine at 1,500 rpm and allow engine to return to idle.
  • Operate the blower motor in all control positions and check for correct blower speed changes.
  • With the blower motor on HI, operate air discharge mode selector in all positions and check for correct airflow in each position.
  • Operate the temperature blend selector in all positions and check for correct change in discharge temperature. Check the air discharge temperature with the selector in the coolest position and the air conditioning on and set to MAX A/C to determine if the air discharge temperature is acceptable for the current ambient air temperature.
  • Carry out the EATC self-test (if applicable).

    If the refrigerant system pressures were low, carry out the refrigerant system leak test.

4. Refrigerant system leak test

  • Use either an ultraviolet (UV) or an electronic leak detector to check for leaks at all refrigerant lines, connections, and components.

    After all tests have been completed, report all findings and recommended repairs to your service advisor before carrying out further diagnostic procedures.

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