9. If output is within 10 amperes of rated output, test
regulator with an approved regulator tester, and check
10. If output is not within 10 amperes of rated output,
check the field winding, diode trio, rectifier bridge, and
stator as previously covered.
Fig. 16 - Tighten Alternator Pulley Retaining Nut
Fig. 15 - Connections for Generator Bench Check
1. Install the drive pulley, if it was removed. Tighten
Ground polarity of battery and
the pulley retaining nut to 50-60 lb-ft (68-81 Nm) torque
Use a fully charged battery, and a 10 ohm resistor rated
at six watts or more between the alternator No. 1
If the pulley was not removed, check
terminal and the battery.
the retaining nut for proper torque.
2. Position the alternator on the mounting brackets and
2. Slowly increase the alternator speed and observe the
start the bolts, with washers in place, through the bolt
holes in the end frames. Insert the bolts through the bolt
3. If the voltage is uncontrolled with speed and
holes in the mounting bracket and end frame. Make
increases above 15.5 volts, test regulator with an
sure that the washers and nuts are in their proper
approved regulator tester, and check field winding.
3. Align the threaded hole in the adjusting lug of the
The battery must be fully charged
drive end frame with the slot in the adjusting strap. Start
when making this check.
the bolt, with the washers, through the slot of the
4. If voltage is below 15.5 volts, connect the carbon pile
adjusting strap and into the threaded hole in the end
5. Operate the alternator at moderate speed as required
4. Place the drive belt in the groove of the pulley.
and adjust the carbon pile as required to obtain
maximum current output.
Tighten all of the bolts after the belt tightening is
6. If output is within 10 amperes of rated output as
stamped on alternator frame, is good.
6. Attach the wires and cables. Be sure that each one
7. If output is not within 10 amperes of rated output,
is correctly installed in accordance with its previous
keep battery loaded with carbon pile, and ground
location on the alternator. Keep all connections clean
8. Operate alternator at moderate speed and adjust
carbon pile as required to obtain maximum output.