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 Switch

Turn ignition Off, then connect suitable ohmmeter between center terminal of temperature switch and ground for coolant temperature switch or between center terminal and ground terminal of charge temperature switch.
- With engine cold, continuity should be present with resistance less than 100 ohms. If not, replace switch. Charge temperature switch must be cooler than 60°F in order to perform test properly.
- With engine hot, terminal reading should show no continuity. If continuity is present, replace coolant switch.