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Field Circuit Drain Testing

NOTE: Connect voltmeter negative lead to alternator rear housing for all the following voltage readings.
  1. Turn ignition switch to OFF position. Connect voltmeter positive lead to terminal "F" screw head. See Figure. Battery voltage should be indicated. If less than battery voltage is indicated, go to next step. If battery voltage is indicated, system is functioning properly and further testing is not needed.
  2. Connect positive voltmeter lead to terminal "I" of wiring harness connector (with ignition off). See Figure. If no voltage is indicated, go to next step. If voltage is indicated, repair circuit "I" from ignition switch to eliminate voltage source.
  3. Connect positive voltmeter lead to terminal "S" of wiring harness connector (with connector connected to regulator). If voltage is indicated, go to next step. If no voltage is indicated, replace regulator.
  4. Disconnect wiring harness connector from regulator. Connect voltmeter positive lead to terminal "S" of wiring harness connector. See Figure. If voltage is indicated, repair wiring harness to eliminate voltage source. If no voltage is indicated, replace alternator rectifier assembly.
NOTE: Digital ohmmeter CANNOT be used for bench tests.
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