Compressor HVAC: Testing and Inspection
INSPECTIONTHERMAL FUSE
1. A thermal fuse is located on the compressor clutch coil.
2. The thermal fuse will detect clutch slip heat (184 °C off) generated by faulty compressor operation, then interrupt the coil's power supply. Therefore, the clutch bearing and the pulley bearing will not be damaged, also protecting the belt and engine. Once the thermal fuse blows the compressor will not operate. Check the clutch oil resistance (3.0-3.2 ohm) to determine the thermal fuse condition, and replace the clutch coil if required.
MAGNETIC CLUTCH OPERATION
Connect the compressor terminal to battery (+) and the battery (-) terminal to the compressor body. Verify magnetic clutch operation by a clicking noise.