Mercury 1F2Z-12029-AC Ignition Coil Assembly

To check a coil's primary resistance, disconnect the coil's electrical connector and use an ohmmeter across the primary terminals. The resistance should be under 5.0 ohms. If it's a high or open circuit, the coil might be faulty. To replace the coil, disconnect the battery's negative cable, the ignition coil connector(s), and spark plug wires. Remove the coil's securing bolts and install the new coil. Coat the rubber boot interior with Silicone Dielectric Compound and insert the spark plug wires into the terminals. Reinstall the radio ignition interference capacitor if needed.