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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Primary Tests

Ignition Coil:




Coil Schematic Diagram:






1. With the ignition switch OFF, disconnect the primary wire connector and the coil wire.

2. Using an ohmmeter, measure resistance between the terminals A - B:

Resistance value
0.6 - 0.8 ohms

3. Using an ohmmeter, measure for continuity between the terminals A - B. If no continuity, replace coil.

4. Using an ohmmeter, measure resistance between the terminal A - secondary windings:

Resistance value
14,000 - 22,000 ohms

5. If ignition coil fails any of the above tests replace ignition coil

NOTE: Resistance will vary with the coil temperature, specifications are at 68°F (20°C)