Ford Mustang (1999-2004) Service Manual: Dual-Function Pressure Switch (4.6L)

Dual-Function Pressure Switch (4.6L)

The dual-function pressure switch is used to interrupt A/C compressor operation in the event of high system discharge pressures.

  • The dual-function pressure switch is mounted on a Schrader valve-type fitting on the high pressure side of the A/C manifold and tube.
  • It is not necessary to discharge the refrigerant system to remove the dual-function pressure switch.
  • A valve depressor, located inside the threaded end of the dual-function pressure switch, presses on the Schrader valve stem.
  • This allows the dual-function pressure switch to monitor the compressor discharge pressure.
  • When the compressor discharge pressure rises, the switch contacts open, disengaging the A/C compressor. When the pressure drops, the contacts close to allow operation of the A/C compressor. For specifications regarding operating pressure(s), refer to Section.

The dual-function pressure switch has a second set of electrical contacts used for high-speed cooling fan control.

When the compressor discharge pressure rises, the contacts close and engage the high speed fan control. When the pressure drops, the contacts open and the high speed fan control is disengaged.

Refrigerant Containment Switch (3.8L)

The refrigerant containment switch is used to interrupt A/C compressor operation in the event of high system discharge pressures.

  • The refrigerant containment switch is mounted on a Schrader-type valve fitting on the high pressure side of the compressor manifold and tube assembly.
  • A valve depressor, located inside the threaded end of the refrigerant containment switch, presses on the Schrader valve stem.
  • This allows the refrigerant containment switch to monitor the A/C compressor discharge pressure.
  • When the A/C compressor discharge pressure rises, the switch contacts open, disengaging the A/C compressor. When the pressure drops, the contacts close to allow operation of the A/C compressor. For additional information regarding operating pressure(s), refer to Section.
  • It is not necessary to discharge the refrigerant system to remove the refrigerant containment switch.
    Suction Accumulator
      NOTE: Installation of a new suction accumulator is not required when repairing the air conditioning system except when there is physical evidence of contamination from a failed A/C compres ...

    Spring Lock Coupling
      The spring lock coupling is a refrigerant line coupling held together by a garter spring inside a circular cage. When the coupling is connected together, the flared end of the female f ...

    Other materials:

    Functionality
    With the ignition switch in the RUN position, voltage is applied through the warning indicator I circuit 904 (LG/RD) to the voltage regulator. This turns the regulator on, allowing current to flow from battery sense A circuit 36 (YE/WH) to the genera ...

    Rear Bumper Cover
    Removal and Installation 1. Remove the luggage compartment trim panel covers. 2. Remove the seven rear bumper cover nuts. 3. Remove the fuel drain hose. 4. Remove the four bumper cover screws (two each side). 5. Remove the pin-type retainers and the rea ...

    Valve Spring Strength
    Special Tool(s) Pressure Gauge, Valve/Clutch Spring 303-006 (TOOL-6513-DD) or equivalent 1. Use a Valve/Clutch Spring Pressure Gauge to check the valve spring for correct strength at the specified valve spring length. Refer to the appr ...