Refrigerant Pressure Sensor / Switch: Testing and Inspection

Triple Pressure Switch




The triple pressure switch is a combination of the low pressure switch (for checking the quantity of refrigerant) and the high pressure switch (for prevention of overheating) and medium pressure switch (for operating cooling fan and condenser fan at high mode). It is installed in the receiver, and, when the pressure becomes approximately 200 kPa (29 psi) or lower, the compressor stops, thus preventing the compressor from being damaged by heat. When the pressure reaches 3,241 kPa (470 psi) or higher, the compressor stops, thus preventing overheating. There is generally no necessity for inspection; if, however, an unusual condition, such as non-operation of the compressor is encountered, check by following the procedures below.

ON-VEHICLE INSPECTION
1. Disconnect connector of the pressure switch.
2. Install the manifold gauge set.
3. Observe the gauge reading.
4. Check the continuity between the two terminals of the pressure switch shown in the figure. If defective, replace the pressure switch.