Refrigerant Pressure Sensor / Switch: Description and Operation

A/C Pressure Switch -F129-

Where applicable, the A/C pressure switch is a combination switch (two switching components) that protects refrigerant circuit components from malfunctioning due to excessive or insufficient refrigerant system pressures.
- Switch part between terminals 1 and 2 switches off the A/C clutch -N25- when the system pressure is too high or when there is not enough refrigerant in the system.
- Switch part between terminals 3 and 4 switches coolant fan -V7- to the next higher fan speed when system pressures increase.

NOTE: Always confirm system use of-F129- described above, and applicable wiring circuit using applicable "Engine" and "Climatronic" wiring diagrams.