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

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

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Coolant Temperature Sensor / Switch HVAC: Testing and Inspection

1. Remove switch from thermostat housing, then place switch and thermometer in water.
2. Gradually heat water and check continuity with an ohmmeter. If temperature is above 207°F, continuity should exist. If temperature is below 207°F, continuity should not exist.
3. If continuity is not as specified, replace switch.