Dual Function Pressure Switch: Notes
WARNING: This page is about a different car, the 2005 Mercury Sable and 2005 Ford Taurus. However, it is still accessible from the selected car via links, so may be relevant.
The dual function pressure switch (19D594) 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-type valve fitting on the compressor manifold and tube assembly.
- It is not necessary to recover the refrigerant when removing the dual function pressure switch.
- A valve depressor, located in the threaded end of the dual function pressure switch, presses on the Schrader-type 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 compressor discharge pressure drops, the switch contacts close to allow operation of the A/C compressor. For specifications regarding operating pressure(s), refer to CLIMATE CONTROL SYSTEM-GENERAL INFORMATION .
- 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 cooling fan control. When the pressure drops, the contacts open and the high-speed cooling fan control is disengaged. For additional information, refer to ENGINE COOLING .