Ambient Temperature Sensor / Switch HVAC: Testing and Inspection

1. Remove wires from ambient sensor switch. Check continuity of the ambient switch. Switch contacts are closed at temperatures above 10°C (50°F). If no continuity, replace the switch.
2. If contacts are closed, verify switch operation as follows. Place crushed dry ice on the switch housing for a minimum of 30 seconds, the contacts are open. If this condition is not met the switch should be replaced.

WARNING: ALWAYS WEAR PROTECTIVE GLOVES WHEN HANDLING DRY ICE TO PROTECT HANDS FROM INJURY.