How to Test an Ignition Coil

How to Test an Ignition Coil

This testing procedure is valid for just about any automotive ignition coil.

Using an ohmmeter, check the resistance between the side terminals of the coil. Do this with all of the wires to the coil disconnected. You should see 0.75 to 0.81 ohms of resistance.

Then, check the resistance between either side terminal and the center high tension terminal. The reading should be 10,000 to 11,000 ohms.


Any significant deviation from these numbers indicates that the coil is defective.

Ignition Coil Test:

HEI Ignition Coil Test: