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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Vacuum Switch: Testing and Inspection


1. Disconnect vacuum hose and vacuum switch connector.
2. Using suitable vacuum pump, apply vacuum to vacuum switch and check continuity through vacuum switch. There should be no continuity between terminals "C" and "NO" when intake manifold is above 22.83 inches Hg, and continuity should exist between terminals "C" and "ON" when intake manifold is below 22.83 inches Hg.