High Pressure Sensor / Switch: Testing and Inspection

Review General Information Safety Precautions before proceeding with this operation. This test requires the use of a Manifold Gauge Set.

Test must be conducted at a minimum ambient temperature of 21°C (70°F).
a. Connect a manifold gauge set to the compressor discharge port.
b. Set the A/C controls to Panel or A/C and High blower, operate the engine at 1300 rpm.
c. Monitor the compressor discharge pressure, the HPCO Switch should disengage the compressor clutch when the discharge pressure reaches 2756 ± 69 kPa (400 ± 10 psi). If this pressure can not be obtained, restrict air flow through the radiator. The compressor clutch should re-engage when the decreasing discharge pressure reaches no lower than 1826 kPa (265 psi).