Inspection of HVAC Control Module and Its Circuits: Notes

NOTE: If you connect a voltmeter or ohmmeter directly to the HVAC control module by disconnecting the HVAC control module connector, you can damage the HVAC control module.
Never connect a voltmeter or an ohmmeter directly to any terminal on the HVAC control module by disconnecting the HVAC control module connector.

HVAC control module and its circuits can be checked at HVAC control module wiring connector by measuring voltage and pulse signal.