TM 5-3740-218-13&PTable 5-1. Direct Support Troubleshooting (Cont)MalfunctionTest or InspectionCorrective Action•Check oil level and key switches for continuity between pins1-2, 1-4, 1-5, 2-4, and 4-5. There should be no continuitybetween pins 1-3, 2-3, 2-5, 3-4, 3-5.With multimeter set to ohms scale, measure resistancebetween 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 inone direction. If reading shows continuity in both directions,replace rectifier (para 5-5).Step 2. Check for defective starter motor.WARNINGBe careful not to contact high-voltage connections when installing or operating this equipment.NOTECranking under load indicates hydraulic pump installed on engine. Cranking with no load indicateshydraulic pump removed from engine.•Connect battery.•With multimeter set to read 12 VDC, measure crankingvoltage under load across starter leads. Reading should be9.9 VDC. Measure cranking voltage with no load. Readingshould be 11.5 VDC. If starter motor fails to meetperformance voltage readings, repair or replace starter motor(para 5-7 or 5-6).•With multimeter set to read amps, measure crankingamperage under load. Reading should be below 103 amps.Measure cranking amperage with no load. Reading should bebelow 31 amps. If starter fails to meet performance amperagereadings, repair or replace starter motor (para 5-7 or 5-6).•With multimeter set to read 12 VDC, check for 12 VDCbetween starter terminal and solenoid terminal. If no voltageis present, replace starter motor (para 5-6).•Measure length of starter motor brushes. Length should be0.14-0.28 in. (3.5 mm-7.0 mm). If brush length is inadequate,replace brushes (para 5-7).5-4
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