Operation CHARM: Car repair manuals for everyone.

Spark Plug Wires

The spark plug wires connect the ignition control module to the spark plugs. It incorporates several plastic channels and conduits to keep it properly positioned and to protect it. The spark plug wires are 7 mm in diameter and the outer jacket is made of silicone to withstand high temperatures. The silicone jacket is also an excellent insulator for the high voltages used in the ignition system. The silicone spark plug boots provide a tight seal on the spark plug. Care should be exercised when connecting a timing light or other equipment. Do not force anything between the boot and wiring or through the silicone jacket. Connections should be made using an appropriate adapter.