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: Checking Dual Pressure Switch

   Courtesy of SUZUKI OF AMERICA CORP.
2. Using a manifold gauge set, check switch for operation specified pressure as shown, see 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: Checking Dual Pressure Switch

Courtesy of SUZUKI OF AMERICA CORP.