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Ignition Coil (HEI)

  1. Connect an ohmmeter between the tach terminal and battery terminal. See Meter "A" in Fig 1. Use the high resistance scale. If ohmmeter does not indicate zero or nearly zero, replace coil.
  2. Connect ohmmeter between the cap button and negative terminal. See Meter "B" in Fig 1. Use the high resistance scale. Record reading. Connect ohmmeter between cap button and tach terminal. Record reading. If both readings are infinite, replace coil.
Fig 1: Coil Test Connections
G9011Courtesy of GENERAL MOTORS CORP.