ARMY TM 9-6115-639-13 AIR FORCE TO 35C2-3-386-51 MARINE CORPS TM 10155A-13/1 Table 4-4.  Unit Level Troubleshooting MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION 1.      ENGINE WILL NOT CRANK a.    Check battery for loose connections, corrosion, damaged cable. Clean battery terminals and tighten connections. b.    Check battery voltage as follows: (1) Connect positive (+) probe of multimeter to terminal board TB3, test point TP30. (2) Connect negative (-) probe to TB3, test point TP31. (3) Place START / RUN / STOP switch in START position. (4) 20 to 32 VDC present? If not present, service battery (Para. 4-44).  Replace as required. c.    Check START / RUN / STOP switch as follows: (1) Connect positive (+) probe of multimeter to terminal board TB5, pin 11. (2) Connect negative (-) probe to TB3, test point TP31. (3) Place START / RUN / STOP switch in START position. (4) 20 to 32 VDC present? If not present, remove and replace START / RUN / STOP switch (Para. 4-19). d.    Check diode CR1 as follows: (1) Connect positive (+) probe of multimeter to terminal board TB5, pin 9. (2) Connect negative (-) probe to TB3, test point TP31. (3) Place START / RUN / STOP switch in START position. (4) 20 to 32 VDC present? If not present, remove and replace diode (Para. 4-25). e.    Check relay K15 as follows: (1) Place START / RUN / STOP switch in STOP position. (2) Remove relay K15 and ohm out pins 1 and 9. (3) Zero ohms at relay K15, pins 1 and 9? If not zero ohms, remove and replace relay (Para. 4-24). f.     Check engine start contactor K2: (1) Disconnect wires from K2, terminals 1 and 2. (2) Connect multimeter probes to K2, X1 and X2. (3) Resistance should be approximately 55 ohms. If multimeter indicates infinity or 0 ohms, replace K2.  (Para. 4-28). 4-14 Change 1