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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Spark Plug Wire Resistance

TOOLS REQUIRED
J 39200 Digital Multimeter

1. Disconnect both ends of each spark plug wire YOU are testing.
Ensure that the wire terminals are clean before proceeding.
2. Use the J 39200
3. Connect an ohmmeter lead to each end of the wire.
4. Gently twist the wire while watching the ohmmeter reading.
5. It the ohmmeter reads above 30,000 ohms, no matter how long the wire is, or fluctuates from infinity to any value, replace the wire.