thoroughly. Blow all dust from brush area with low
pressure compressed air.
Caution
Do not operate the alternator simultaneously
(2) Visually inspect all mounting hardware for
with a DC generator on a common battery
wear or stripped threads. Inspect alternator for cracks or
circuit.
breaks in pulley, housing, or end bells. Inspect belt for
wear, frayed condition, or deterioration.
(3) Repair by replacing defective hardware,
b. On Equipment Test.
belt, or alternator.
e. Belt Removal, Installation, and Adjustment.
(1) Disconnect battery cables and tie back to
(1) Removal and installation.
Remove
prevent accidental flash current.
alternator belt in manner similar to that described for
(2) Tag accurately for position, then remove all
generator (para 3-77). Install in reverse order.
electrical leads from alternator.
(2) Adjustment.
Adjust generator belt as
(3) Use automotive generator and voltage
shown on figure 3-17.
regulator test set and hook up as illustrated in figure 3-60.
(4) Operate the alternator at approximately
3-79. Generator Regulator (For Engine Model 687C-
2,500 RPM.
18-ES)
Caution:
Do not allow voltage to exceed the
a. On Equipment Test.
recommended voltage setting of the
regulator.
(1) Remove electrical leads from voltage
regulator (fig. 3-58).
(2) Test voltage regulator in conjunction with
(5) Adjust the load rheostat to obtain 28 volts.
generator (para. 3-77) by using connections illustrated in
When the correct voltage is obtained, the ammeter should
view B, figure 3-61. Polarize generator by momentarily
read 61 amperes.
touching jumper wire as shown in view A.
(6) If the correct output is not obtained, replace
(3) Start generator and gradually increase
the alternator.
speed until cutout relay points close. Closing voltage
(7) If the correct output is obtained and the
should be 26 volts.
batteries are not charging correctly, check remainder of
(4) With generator operating at 4,000 RPM,
the charging circuit (view B of fig.1-9).
reading on voltmeter should be 28.2 volts, and ammeter
(8) Remove test set harness, reconnect all
should read 40 amperes.
electrical leads, then remove tags.
(5) If requirements of (3) and (4) above are not
(9) Install battery cables.
met, regulator is defective, and must be replaced.
c. Removal and Installation.
(1) Remove battery cables 'and tie back to
Note.
prevent flash currents.
Do not remove voltage regulator
(2) Tag correctly for position, then remove all
except when replacement is required
electrical leads from alternator.
(3) Remove alternator in manner similar to that
described for generator (para 3-77).
and remove items. 1 through 4 in numerical sequence to
remove voltage regulator. Items 5 through 8 removes
shock mount. Install in reverse order.
3-80. Alternator Voltage Regulator (For Engine Model
D333TA)
a. General. The alternator voltage regulator senses
Figure 3-60. Alternator test connections .
charge condition of batteries as well as electrical system
d. Cleaning, Inspection and Repair.
power demand, and controls alternator output accordingly.
(1) Clean exterior of alternator with a rag
As battery charge increases, charging rate decreases,
dampened in an approved cleaning solvent then dry
until batteries
3-71
