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

NOTE: This test should be conducted with the coil disconnected completely. Make sure to make note of wire locations for reassembly.

1. Measure the primary ignition coil resistance between the positive (+) and the negative (-) coil terminals using a digital volt ohm meter. Primary coil resistance (cold) should be 1.35 to 1.65 ohms. If the resistance is NOT within specification, the coil must be replaced.

2. Measure the secondary coil resistance between the positive (+) and the coil wire terminal. Secondary resistance should be 11 to 14.5K ohms. If the resistance is NOT within specification, the coil must be replaced.