Ignition Coil Resistance Checks
- If ignition coil is suspected, connect ohmmeter leads to positive and negative primary terminals. Ignition switch should be "OFF" and coil wires removed. Primary resistance should read 1.60-1.79 ohms for Prestolite coils; 1.34 to 1.55 ohms for Essex coils.
- Then move ohmmeter leads to coil negative terminal and coil tower. Ohmmeter resistance reading should be 9, 400-11, 700 for Prestolite coils, 9, 000-12, 200 ohms for Essex coils.
- Replace ignition coil if either specification is not obtained.