Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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Compressor Clutch Diode HVAC: Testing and Inspection

Diode Test
NOTE: The diode is designed to pass current in one direction while blocking it in the opposite direction. Use an analog ohmmeter, or a digital ohmmeter equipped with a diode tester.





Check for current flow in both directions between the A and B, and B and C terminals. There should be current flow in only one direction.