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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Evaporator Temperature Sensor / Switch: Testing and Inspection

A/C Thermostat Test




Dip the A/C thermostat into a pan filled with ice water, and check for continuity between the terminals.

Cut off 1.5 - O.5°C (35 - 33°F)
Cut in 2.5 - 5°C (36-41°F)


If cut off or cut in temperature is too low or too high, replace the A/C thermostat.