Dual Pressure Cut-Out Switch
Dual pressure cut-out switch, located on compressor manifold, monitors refrigerant pressure. This information is sent to Powertrain Control Module (PCM), which uses this information to control cooling fan and compressor clutch.
When discharge pressure decreases to about 220-280 psi (15.5-19.7 kg/cm2 ), dual pressure cut-out switch contacts will close, energizing compressor (magnetic) clutch coil. When discharge pressure increases to about 435-475 psi (30.6-33.4 kg/cm2 ), dual pressure cut-out switch contacts will open, de-energizing compressor clutch coil.
When A/C is turned on, cooling fan operates at low speed. When discharge pressure is about 310-340 psi (21.8-23.9 kg/cm2 ), dual pressure cut-out switch contacts will close and cooling fan will operate at high speed. When discharge pressure decreases to 240-310 psi (16.9-21.8 kg/cm2 ), dual pressure cut-out switch contacts will open and cooling fan will operate at low speed.