Dual (Refrigerant) Pressure Switch Inspection

1. Check dual pressure switch (1) on liquid pipe for continuity at normal temperature (approx. 25°C, 77°F) when A/C system has a proper charge of refrigerant and when A/C system (compressor) is under operation. In each of these cases, switches should show proper continuity.
   Fig 1: Identifying Dual Pressure Switch

   Courtesy of SUZUKI OF AMERICA CORP.
2. Using a manifold gauge set, check switch for operation specified pressure as shown, refer to "PERFORMANCE DIAGNOSIS OF A/C SYSTEM:  ".

Dual pressure switch specification 

Switch ON: above "C" and below "D" 

Switch OFF: below "A" or above "B" 

"A": Approx. 200 KPa (2.0 kg/cm ² )

"B": Approx. 3200 kPa (32 kg/cm ² )

"C": Approx. 23 kPa (2.3 kg/cm ² )

"D": Approx. 2800 kPa (28 kg/cm ² )

Tightening torque 

Dual pressure switch: 10 N.m (1.0 kg-m, 7.5 lb-ft) 

Fig 2: Dual Pressure Switch Continuity Graph

Courtesy of SUZUKI OF AMERICA CORP.