TM 5-3740-218-13&P
Table 5-1. Direct Support Troubleshooting (Cont)
Malfunction
Test or Inspection
Corrective Action
Check oil level and key switches for continuity between pins
1-2, 1-4, 1-5, 2-4, and 4-5. There should be no continuity
between pins 1-3, 2-3, 2-5, 3-4, 3-5.
With multimeter set to ohms scale, measure resistance
between black and green leads, and yellow and green leads.
If readings exceed 1 M ohm, replace key switchbox (para 5-5).
With multimeter set to ohms scale, check for continuity in
one direction. If reading shows continuity in both directions,
replace rectifier (para 5-5).
Step 2. Check for defective starter motor.
WARNING
Be careful not to contact high-voltage connections when installing or operating this equipment.
NOTE
Cranking under load indicates hydraulic pump installed on engine. Cranking with no load indicates
hydraulic pump removed from engine.
Connect battery.
With multimeter set to read 12 VDC, measure cranking
voltage under load across starter leads. Reading should be
9.9 VDC. Measure cranking voltage with no load. Reading
should be 11.5 VDC. If starter motor fails to meet
performance voltage readings, repair or replace starter motor
(para 5-7 or 5-6).
With multimeter set to read amps, measure cranking
amperage under load. Reading should be below 103 amps.
Measure cranking amperage with no load. Reading should be
below 31 amps. If starter fails to meet performance amperage
readings, repair or replace starter motor (para 5-7 or 5-6).
With multimeter set to read 12 VDC, check for 12 VDC
between starter terminal and solenoid termnal. If no voltage
i
is present, replace starter motor (para 5-6).
Measure length of starter motor brushes. Length should be
0.14-0.28 in. (3.5 mm-7.0 mm). If brush length is inadequate,
replace brushes (para 5-7).
5-4
