(5) Test the second air in a similar manner.
(1) Remove slip ring end frame (a above).
(6) Proceed to rep of diodes and test in
(2) Connect ohmmeter leads between either
similar manner m (4) and (5) above.
slip ring and rotor shaft. Observe readings. Reading
(7) Replace defective diodes (e above).
should be very high (full scale). If a low reading is
obtained, the windings are grounded and should be
g. Testing the Stator.
replaced.
NOTE
(1) Remove stator from split ring end frame (c
A test lamp should not light when
above).
connected between one slip ring and
(2) Connect one ohmmeter test probe to o
the shaft.
one of the three stator leads, then touch stator frame
with remaining test probe Observe ohm meter reading.
(3) Connect one ohmmeter lead to each slip
This reading should be very high (full scale). A low
ring. Low resistance should be indicated (approximately
reading indicates a grounded stator winding. Replace
two ohm). If a high reading is observed, the windings are
the stator when a low reading is observed.
open and should be noted
(3) Touch the test probes to any two of the
A test lamp should light when connected between the
stator leads.
Zero resistance should be read on
two slip rings.
ohmmeter.
When high resistance is read, stator
(4)
Windings can be checked for short-circuits by
windings are open, and stator must be replaced
connecting a battery and ammeter in series with the two
slip rings. Note the ammeter reading. It should read
NOTE
between 3.6 and 4.0 When high amperage is indicated,
A test lamp should light when con -
winding are shorted and should be replaced.
nected between the two slip rings.
h. Rotor Test.
Section II. STARTER MOTOR
(3) Remove bushing (1) from drive housing
3-4. General
(2), then remove pipe plug (19) and wick (20).
(4) Remove electric engine drive (4) and
The electric starter motors on these diesel engines are
thrust washer (8) from drive housing (2).
24 volt heavy duty type and of similar construction. The
(5) Remove plate (6) from armature (22).
instructions in this section will cover details of the starter
(6) Remove bearing (5) from plate (6).
motor on engine model 687C-18-ES. Maintain the
(7) Remove four screws (41) and lockwashers
starter motor of engine model D333TA in a similar
(17) securing commutator end bell (40) to housing (12).
manner
(8) Back end bell (40) from housing (12),
loosen screws (80), remove field coil leads from brushes
3-5. Starter Motor
(28), and remove end bell (40) from housing (12).
(9) Remove pipe plug (19), wick (46), and
a. Removal and Installation. Refer to TM 5-3810-
pipe plug (43), from end bell (40).
201-12 and remove or install the starter motor.
(10) Remove nut (10), lockwasher (8), nut (44),
flatwasher (45), flatwasher (47), insulator bushings (48
b. Disassembly (Starter Used on Engine Model
and 49), and brush holder (36) from end bell (40).
687C-18-ES).
(11) Remove screw (80), lockwasher (29), and
brushes (28) from brush holder (32) and field coil wires
(1) Remove two screws (16, fig. 3-3) and
(12) Remove screws (24, 26, and 50), springs (2),
cover band (15) from housing (12).
lockwashers
(27),
brush
holders
(2) Remove six screws (18), lockwashers
(17), and electric engine drive housing (2) from housing
(12).
3-5
