When your Chrysler spark plug wires go bad, the problem can usually be traced to the exterior of the plug wires. That's the insulation jacket, which can deteriorate under the pressure of heat, as well as the corrosive effects of oil, moisture and gases. The insulation jackets may be damaged by abrasion that stems from a vibrating engine. Spilled fluids or battery acid can eat away at the jacket materials. If the wires have been disconnected and reconnected multiple times, the wear and tear will make the jacket crack. And every once in a while, animals will gnaw on the spark plug wires when they make a nest in your car engine. When that wire jacket goes bad, the spark may leak out and jump to a nearby ground on the engine. That's because high-voltage electricity in your car's combustion system looks for an easier path to jump across than a pair of electrodes in a spark plug. The wire jacket contains the electricity with a thick jacket of insulation. If that outer jacket is damaged, the electricity may leak out to follow the easier path. Often, a visual inspection will reveal that the Chrysler spark plug wire exterior has been damaged. Replace any wires that show damage such as a cut, grooves or marks from chafing or scorch marks from burning (another sign that arcing is occurring because of leaking electricity). These should be replaced immediately as a matter of safety.