Yes, I forgot to mention a spare ICM option ... but we've been 'round that flagpole extensively.
Also, my post focuses on the ignition system. It assumes the rest of your electrical system is in good condition. A good, fully charged battery, functioning alternator and voltage regulator, and good positive and negative/ground cables, wires and connections.
Specifically worth mentioning is the potential impact the starter has on the ignition system. A good ignition system could appear to be malfunctioning of the starter is failing or doesn't have good cables, wires, and electrical connections.
The starter requires a tremendous amount of electrical current. If there are issues with the starter itself or its electrical supply, it will require even more current. The result could be not enough electricity left for the ignition system to 'do its thing.'
