TRUCK SERVICE MANUAL
ELECTRICAL
each of the other two connectors. NOTE: Diode trios
Repeat this same test between the same heat sink
differing in appearance may be specified for use in the
and other two metal clips and between the other heat
sink and the three metal clips.
same integral charging system, and the two are
completely interchangeable.
CAUTION: Do not use high voltage, such as 110-volt
test lamp, to check the rectifier bridge.
Stator Checks
(Omit for overcharged battery)
The stator windings may be checked for grounds with a
110volt test lamp or an ohmmeter. If the lamp lights or if
the meter reading is low when connected from any stator
lead to a clean metal part of the frame, the windings are
grounded, Fig. 10. The delta windings cannot be
checked for opens or for short circuits without laboratory
test equipment. However, if all other electrical checks
are normal and the generator fails to supply rated output
but will supply at least 10 amperes output, shorted stator
Fig. 8
windings are indicated.
Rectifier Bridge Check
(Omit for overcharged battery)
Note that the rectifier bridge has a grounded heat
sink and an insulated heat sink, Fig. 9
to a heat sink and one of the flat metal clips and not to
threaded stud. Press down firmly onto flat metal clip.
Then reverse lead connections. If both readings are the
same, replace the rectifier bridge.
Fig. 10
Brush Holder and Regulator Replacement
After removing the stator and diode trio, the brush
holder and regulator may be replaced by removing the
two remaining screws. Note the two insulated screws in
Fig. 6. These screws have special insulating sleeves
over the screw body above the threads. The third screw
may or may not have an insulating sleeve. Do not
interchange screws if one does not have an insulating
sleeve. A ground could result causing no output or
uncontrolled output of alternator.
Fig. 9
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