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)

Or, hide this message: temporarily or permanently

Ignition Coil: Testing and Inspection

1. Remove the distributor cap.

2. Connect one end of an ohmmeter to the (-) side of the ignition coil. Connect the other end to the (+) side of the ignition coil.

Primary Coil Resistance:






Primary Resistance (Cold): 0.38 - 0.46 ohms

3. Connect one end of an ohmmeter to the high tension terminal of the ignition coil. Connect the other end of the ohmmeter to the (+) side of the ignition coil.

Secondary Coil Resistance:






Secondary Resistance (Cold): 7.7k - 10.4k ohms

4. If Primary or Secondary coil resistance value is not within specifications, replace ignition coil. For further information refer to SPARK TEST.