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Spark Plug Wire Resistance Check

  1. Remove distributor cap and disconnect spark plug end of suspected wire(s). Connect ohmmeter leads from terminal inside distributor cap to end of spark plug wire. Never puncture spark plug wire when measuring resistance.
  2. If resistance is below 7000 ohms per foot, visually inspect wires for damage and service spark plug if necessary. If resistance is over 7000 ohms per foot, disconnect suspected wire from distributor cap and reconnect leads to each end of wire.
  3. If resistance is now less than 7000 ohms per foot, inspect distributor cap and spark plug wire terminals for damage. Repair as necessary. If resistance is still greater than 7000 ohms per foot, replace wire(s).