Refrigerant Pressure Sensor / Switch: Testing and Inspection

1. Locate and disconnect wire connector at the damped pressure switch.
2. Check continuity of the switch. The switch contacts are closed above 45°F (7°C). If there is no continuity, replace the switch.
3. If the contacts are closed, verify switch operation as follows:
a. Reconnect wires to pressure switch.
b. Set temp. control lever to full cool position.
c. Set blower motor on low speed and press A/C button.
d. Operate engine at 1300 rpm for approximately 5 minutes to stabilize.
e. If compressor clutch cycles on & off 2 to 3 times per minute with temperatures between 68°F to 90°F (20°C to 32°C), the switch is normal. If compressor clutch fails to engage, check for continuity in circuit. Above 90°F (32°C) the compressor clutch may be continuously engaged due to high heat load, this condition is normal.