| |
TM 10-3930-638-24&P
3-10. STARTER AND SOLENOID TROUBLESHOOTING (cont)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Armature
Current
Probable
Inspection
Speed
Draw
cause
Data
High
Low
High
Zero
Zero
Open field circuit.
Open armature coils.
Poor brush contact.
Zero
Grounded terminals or fields.
Frozen bearings.
Low
High internal resistance.
Low
Excessive friction.
Shorted armature.
Grounded field coils or
armature.
High
High
Shorted field coils.
Check internal connections and field coils for open
condition.
Inspect commutator for badly burned bars after
disassembly.
Check for broken brush springs, worn brushes,
and high insulation between commutator bars.
Disconnect field coil ground connections and check
for grounded condition.
Rotate armature by prying pinion with a
screwdriver.
Check for poor connections, defective leads, and
dirty commutator.
Check for tight, dirty, or worn bearings, bent
armature shaft or loose pole shoes allowing
armature to drag.
Check armature in a growler after disassembly.
Disconnect field coil ground connections and check
for grounded condition.
Replace field coils and repeat bench test.
2. STARTER FAILS TO CRANK
Step 1. Disconnect and tape field coil lead at solenoid M terminal.
Connect solenoid terminals to test set-up as shown.
Close switch, adjust carbon pile for 9 Vdc indication on
voltmeter, and note ammeter reading.
a.
b.
If ammeter indicates 6.5 to 7.0 amperes, proceed
to step 2.
If ammeter does not indicate 6.5 to 7.0 amperes,
replace solenoid switch (para 3-13).
Step 2. Reconnect solenoid terminals to pull-in winding test
set-up as shown on following page.
CAUTION
To prevent overheating solenoid, do not close switch for more
than 15 seconds at a time.
Close the switch and adjust carbon pile for 20 Vdc indication on voltmeter.
Note ammeter reading and open switch.
3-91
|
