Compressor Clutch: Testing and Inspection

A/C Compressor Clutch Check

1. Check the armature plate for discoloration, peeling, or other damage. If there is damage, replace the clutch set. Service and Repair

2. Check the rotor pulley bearing play and drag by rotating the rotor pulley by hand. Replace the clutch set with a new one if it is noisy or has excessive play/drag. Service and Repair






3. Measure the clearance between the rotor pulley (A) and the armature plate (B) all the way around. If the clearance is not within specified limits, remove the armature plate Service and Repair and add or remove shims as needed to increase or decrease clearance.





NOTE: The shims are available in four thicknesses: 0.1 mm, 0.2 mm, 0.4 mm, and 0.5 mm.






4. Check for continuity between the A/C compressor clutch connector No. 1 and No. 2 terminals. If there is no continuity, replace the thermal protector. Service and Repair
NOTE: The thermal protector will have no continuity above about 252 to 262 °F (122 to 128 °C). When the temperature drops below about 241 to 219 °F (116 to 104 °C), the thermal protector will have continuity.






5. Disconnect the field coil connector (A). Check resistance of the field coil. If resistance is not within specifications, replace the field coil. Service and Repair