3-34. VOLTAGE REGULATOR
This task covers:
Tool kit SC 4940-97-CL-E12
Drycleaning solvent (Item 30, Appendix B)
High voltage is used in the operation of equipment. Do not be misled by the term LOW VOLTAGE.
Potentials as low as 50 volts may cause death.
Remove rings, bracelets, wristwatches, and neck chains before working around the locomotive.
Jewelry can catch on equipment and cause injury, or may short across an electrical circuit and cause
severe burns or electrical shock.
With engine running and throttle in No. 8 position, use a multimeter and measure voltage between terminal (1)
of voltage regulator (positive) and negative side of battery switch. Multimeter reading should be 74 1 volt in all
throttle positions. It may be necessary to loosen locking nut (2) and adjust rheostat (3) to obtain correct reading.
Shut down engine.
If regulator is defective, attempt to correct fault by replacing panel control board. If correct test
measurement cannot be obtained after replacing panel control board, replace entire voltage regulator.
Set battery switch to OPEN position. Tag and disconnect voltage regulator wires.