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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Coolant Temperature Sensor / Switch HVAC: Testing and Inspection




1. Dip the air conditioning engine coolant temperature switch in oil and heat the oil with a gas burner or similar item.
2. When the oil temperature reaches the standard value, check that there is no continuity between the switch terminals.

Standard value: 112 - 118 °C (234 - 244 °F)