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 (continued) MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION 19.    ENGINE EMITS BLACK SMOKE a.    Check for clogged, sticking, or worn fuel injector nozzle. If faulty, remove and replace in accordance with TM 9-2815-257-24. b.    Refer trouble to direct support maintenance level. 20.    MALFUNCTION INDICATORS DO NOT ILLUMINATE WHEN PUSH TEST SWITCH IS PRESSED a.    Check for 20 to 32 DC voltage at fault indicator module A2. If not present, remove and replace fault indicator module (Para. 4-18). 21.    ENGINE HIGH TEMP INDICATOR ILLUMINATES a.    Check engine cylinder fins for accumulated dirt and grime.  Check for blockages. Remove blockages.  Clean dirty fins in accordance with TM 9-2815-257-24. b.    Refer trouble to direct support level maintenance. 22.    LOW OIL PRESSURE INDICATOR ILLUMINATES a.    Check for engine oil leaks. Refer to TM 9-2815-257-24 for engine maintenance. b.    Clogged or defective engine oil filter. Remove and replace engine oil filter in accordance with TM 9-2815-257-24. c.    Check engine oil pressure switch OP as follows: (1) Disconnect two wires from oil pressure switch. (2) Check for continuity between switch terminals. (3) With the generator set shut down, the switch should be closed. (4) With the generator set running, the switch should be open. (5) Does switch operate properly? Remove and replace engine oil pressure switch in accordance with TM 9-2815-257-24. 4-25