How to Test a Harley Coil on a 1990 Electra Glide Ultra Classic
The ignitions on Harley-Davidson motorcycles are straightforward systems with only a few components. This is especially true of models made within the decade of the '90s, including the Electra Glide Ultra Classic. One of the ignition components, the coil, is generally made with two sets of wire windings wrapped around an iron core. Testing an ignition coil basically means measuring the resistance between its four terminals. Two are on the primary wind side and two are on the secondary wind side.
- SAE wrench set
Turn off the motorcycle and allow it to cool to the touch.
Remove the spark plug wires from the ignition coil by pulling them by hand. Remove the smaller, primary wires with an open-ended wrench.
Measure the resistance between the two large terminals on the coil with an ohmmeter. The meter should be set to measure Rx1000. The acceptable range for this measurement is 5,500 to 7,500 ohms. Anything outside of this range indicates a faulty coil.
Measure the resistance between the two smaller terminals. The meter should be set to measure resistance on the Rx1 scale. The range for this measurement is 0.5 to 0.7 ohms. Again, anything outside of this range indicates a faulty coil.