Check out this video! The Ignition System
Spark plug wires degrade with time, and can short circuit. This can create a visible “arc”. If your spark plug wires are worn, you may notice one or all of the following:
• Engine hesitation or misfire
• Engine running rough or shaking
• Check engine light on
Spark plug wires need to be changed periodically to maintain smooth engine operation, usually every 7-10 years. It may be recommended to change them when spark plugs are replaced as a preventative measure.