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Test G: System Overcharges (4.0L OHV)

  1. Turn ignition on and measure voltage drop between voltage regulator "A" terminal and battery positive terminal. Connect positive lead to battery positive terminal and connect negative lead to voltage regulator "A" terminal. See Figure . If voltage is less than .5 volt, go to next step. If voltage is .5 volt or greater, repair high resistance in Yellow/White wire between generator and battery junction box. Retest system operation. See WIRING DIAGRAMS  .
  2. Start engine and turn off all accessories. Increase engine speed while measuring voltage between battery terminals. If battery voltage stays at or less than 15 volts, go to next step. If battery voltage increases to greater than 15 volts, go to step  6 .
  3. Turn ignition off. Measure voltage at generator terminal "F". See Figure . If battery voltage is present, go to step  5 . If battery voltage is not present, go to next step.
  4. Ensure ignition is off. Disconnect generator 3-pin and 1-pin connectors. Remove voltage regulator and brush holder. See VOLTAGE REGULATOR  under REMOVAL & INSTALLATION. Measure resistance between each generator slip ring and ground. See Figure . If resistance is greater than 1000 ohms between both slip rings and ground, replace voltage regulator. If resistance between one or both slip rings and ground is less than 1000 ohms, replace generator. See GENERATOR  under REMOVAL & INSTALLATION.
  5. Start engine. Measure battery voltage and observe warning indicator while increasing engine speed. If battery voltage increases to greater than 15 volts, or warning indicator flickers, repair open in Light Green/Red wire between generator and instrument panel. See WIRING DIAGRAMS  . If battery voltage is 15 volts or less and warning indicator does not flicker, replace generator. See GENERATOR  under REMOVAL & INSTALLATION.
  6. Measure voltage between generator terminal "F" and ground while increasing engine speed. If voltage increases with engine speed, replace generator. See GENERATOR  under REMOVAL & INSTALLATION. If voltage does not increase with engine speed, replace voltage regulator. See VOLTAGE REGULATOR  under REMOVAL & INSTALLATION.
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