At every tune-up/inspection, visually check the spark plug cables for burns cuts, or breaks in the insulation. Check the boots and the nipples on the coil or distributor, if equipped. Replace any damaged wiring.
Every 50,000 miles (80,000 km) or 60 months, the resistance of the wires should be checked with an ohmmeter. Wires with excessive resistance will cause misfiring, and may make the engine difficult to start in damp weather. Ignition wire resistance should not be greater than 25 kilohms.
See Figures 1 and 2
To check resistance, disconnect the spark plug wire from the plug and ignition coil or distributor, then use an ohmmeter to measure the resistance.
If resistance falls outside of specifications, the cable(s) should be replaced with new ones.
REMOVAL & INSTALLATION
See Figure 3
As the spark plug wires must be routed and connected properly, if all of the wires must be disconnected from the spark plugs or from the ignition coil pack/distributor at the same time, be sure to tag the wires to assure proper reconnection.
When installing a new set of spark plug wires, replace the wires one at a time so there will be no mix-up. Start by replacing the longest cable first. Twist the boot of the spark plug wire 1 / 2 turn in each direction before pulling if off. Install the boot firmly over the spark plug. Route the wire exactly the same as the original. Insert the nipple firmly onto the tower on the ignition coil or distributor, if equipped. Be sure to apply silicone dielectric compound to the spark plug wire boots and tower connectors prior to installation.