Table 4-2. Organizational Troubleshooting
Test or Inspection
1. GENERATOR FAILS TO BUILD UP RATED VOLTAGE
Inspect for loose connections or loose cable assemblies.
Tighten loose connections and cables.
Check rheostat for proper setting.
Rotate rheostat to obtain exact desired voltage on voltmeter.
Check for defective rheostat by rotating rheostat knob from right to left and left to right and observe voltmeter
needle for respective increase or decrease in voltage.
Connect additional voltmeter to load terminals and take comparative readings to establish validity
of set voltmeter. Visually inspect wire leads at rheostat for breaks or poor solder connections. In-
spect rheostat for breaks or poor wiper contact. Refer to figure 4-21 for DOD model MEP-014A, fig-
ure 4-22 for DOD model MEP-019A and figure 4-23 for DOD model MEP-24A and the following in-
structions to replace a defective rheostat.
Position- LOAD ON/OFF switch (models MEP-014A and MEP-024A), or LOAD ON/OFF
FLASH switch (model MEP-019A) in OFF position.
Close fuel shutoff valve by rotating clockwise to shutoff fuel.
Place ignition switch in OFF position.
Disconnect power source.
Tag and disconnect leads from rheostat. (Figures 4-21,4-22, or 4-23).
Loosen setscrew securing rheostat knob to shaft and remove rheostat knob (Figs 4-21,4-22,
Remove nut securing rheostat to control panel and remove defective rheostat and discard.
Install a new rheostat on control panel and secure with nut.
Place rheostat knob over end of shaft and secure by tightening setscrew.
(10) Reconnect leads to rheostat.
(11) Reconnect power source.
(12) Place LOAD ON-OFF-FLASH switch (model MEP-019A), and LOAD ON/OFF switch (models
MEP-014A and MEP-024A), in OFF position.
(13) Rotate rheostat counterclockwise as far as it will go.
(14) Open fuel shutoff valve. Close the choke (move choke control lever away from flywheel) for
starting cold engine. Open choke (move toward flywheel) gradually as engine starts and
warms until choke is fully open.
(15) Place ignition switch in ON position.
(16) Wind starter rope around starter flange in clockwise direction. Pull rope briskly to start
(17) On model MEP-019A only, place LOAD-ON-OFF-FLASH switch in FLASH position. When en-
gine has attained rated speed, observe panel meter for a voltage indication. Release switch
when voltage reaches a minimum of 100 volts.
(18) If generator output voltage on model MEP-019A fails to develop after set has attained rated
speed, and the LOAD ON-OFF-FLASH switch has been placed in FLASH position, field flash-
ing from an external source will be required. The field is flashed by momentarily connecting
a 12-volt DC source (with resistor of 20 ohms, 5 watts connected in series) to terminals 8 and
7 of TB 2 (fig 1-8). Terminal 8 is positive with respect to terminal 7. The series resistor may be
omitted if voltage polarity is strictly observed.
Reversing field flashing polarity from that indicated above will result in the
destruction of the voltage regulator, rendering the set inoperative.