Operation CHARM: Car repair manuals for everyone.

Ignition Cable: Description and Operation

The spark plug wiring connects the distributor to the spark plugs. Spark plug wires used in this system are composed of four major components:

^ an 8mm (5/16 inch) silicone jacket for high temperature protection. This outer jacket also provides excellent insulation for the high voltages of the ignition system.

^ a reinforcing fiberglass braid for strength.

^ an inner core insulation composed of Ethylene Propylene Diane Monomer (EPDM) for strength and voltage insulation.

^ a Composite High Temperature (CHT) core composed of aramid fibers impregnated with conductive latex and wrapped with conductive silicone.

Care should be exercised when connecting a timing light of other test equipment to the spark plug wires. Do not force anything between the boot and wiring, or through the silicone jacket. Connection should be made in series using an adapter or by using a inductive pickup. DO NOT pull on the wire to remove, pull on the boot, or use a tool designed for this purpose.