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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A/C Signal: Testing and Inspection




1. Connect a voltmeter between terminals 33 and 35 of the injection control unit plug.
2. With A/C OFF, and ignition ON, 0 volts should be available.
3. With A/C in AUTO or BI-LEVEL, battery voltage should be available and compressor clutch should become engaged.
4. If voltages are not correct, repair wiring.