CHAPTER 1 I N T R O D U C T I O NR E P O R T I N G E Q U I P M E N T I M P R O V E M E N T R E C O M M E N D A T I O N S ( E I R S)CAPABILITIES AND FEATURESE Q U I P M E N T D A TASection Ill. TECHNICAL PRINCIPLES OF OPERATIONELECTRICAL SEQUENCE OF OPERATIONMODEL UH-68GSCHEMATICCHAPTER 2 OPERATING INSTRUCTIONSTable 2-1. Controls and Indicators-ContinuedSection Il. OPERATOR PREVENTIVE MAINTENANCE CHECKS AND SERVICES (PMCS)Table 2-2. Operator Preventive Maintenance Checks and ServicesTable 2-2. Operator Preventive Maintenance Checks and Services-Continued - TM-5-4520-253-13_21Table 2-2. Operator Preventive Maintenance Checks and Services-ContinuedTable 2-2. Operator Preventive Maintenance Checks and Services-Continued - TM-5-4520-253-13_23SECTION Ill. OPERATION UNDER USUAL CONDITIONSO P E R A T I O N I N H E A T I N G M O DEOPERATION IN FAN MODE INFORMATION PLATES AND DECALS INFORMATION PLATES AND DECALS CONT. INFORMATION PLATES AND DECALS CONT. - TM-5-4520-253-13_29 INFORMATION PLATES AND DECALS CONT. - TM-5-4520-253-13_30 INFORMATION PLATES AND DECALS CONT.\ INFORMATION PLATES AND DECALS CONT. - TM-5-4520-253-13_32SECTION IV. OPERATION UNDER UNUSUAL CONDITIONS - TM-5-4520-253-13_33CHAPTER 3 UNIT MAINTENANCE INSTRUCTIONSSection Il. REPAIR PARTS, SPECIAL TOOLS, TEST MEASUREMENT DIAGNOSTIC EQUIPMENT (TMDE), AND SUPPORT EQUIPMENTM O U N T E D P O S I T I O N O F H E A T ERR I G H T S I D E M O U N T I NGA D D I T I O N A L I T E M S R E Q U I R EDLOCATION OF HEATERI N S T A L L A T I ONI N S T A L L A T I ON CONT.P R E L I M I N A R Y S E R V I C I N G A N D A D J U S T M E N T O F H E A T ERPREVENTIVE MAINTENANCE CHECKS AND SERVICES - TM-5-4520-253-13_43Table 3-2. Unit Preventive Maintenance Checks and ServicesTable 3-2. Unit Preventive Maintenance Checks and Services-Continued - TM-5-4520-253-13_45Table 3-2. Unit Preventive Maintenance Checks and Services-Continued - TM-5-4520-253-13_46Table 3-2. Unit Preventive Maintenance Checks and Services-Continued - TM-5-4520-253-13_47Table 3-2. Unit Preventive Maintenance Checks and Services-Continued - TM-5-4520-253-13_48Table 3-2. Unit Preventive Maintenance Checks and Services-Continued - TM-5-4520-253-13_49Table 3-2. Unit Preventive Maintenance Checks and Services-Continued - TM-5-4520-253-13_50Section V. TROUBLESHOOTINGTable 3-3. Unit Maintenance TroubleshootingTable 3-3. Unit Maintenance Troubleshooting Continued - TM-5-4520-253-13_53Table 3-3. Unit Maintenance Troubleshooting Continued - TM-5-4520-253-13_54Table 3-3. Unit Maintenance Troubleshooting Continued - TM-5-4520-253-13_55Table 3-3. Unit Maintenance Troubleshooting Continued - TM-5-4520-253-13_56Table 3-3. Unit Maintenance Troubleshooting Continued - TM-5-4520-253-13_57Table 3-3. Unit Maintenance Troubleshooting Continued - TM-5-4520-253-13_58Table 3-3. Unit Maintenance Troubleshooting Continued - TM-5-4520-253-13_59Table 3-3. Unit Maintenance Troubleshooting Continued - TM-5-4520-253-13_60Table 3-3. Unit Maintenance Troubleshooting Continued - TM-5-4520-253-13_61Table 3-3. Unit Maintenance Troubleshooting Continued - TM-5-4520-253-13_62S e c t i o n V I . M A I N T E N A N C E P R O C E D U R E SCONTROL BOX ASSEMBLY PROCEDURES INDEXINSPECT/REMOVE/lNSTALL CONTROL BOX (CONT)l N S P E C T / R E M O V E / l N S T A L L R O O M T H E R M O S T A T R E C E P T A C LElNSPECT/REMOVE/lNSTALL ROOM THERMOSTAT RECEPTACLE (CONT) - TM-5-4520-253-13_67lNSPECT/REMOVE/lNSTALL ROOM THERMOSTAT RECEPTACLE (CONT) - TM-5-4520-253-13_68l N S P E C T / T E S T / R E M O V E / l N S T A L L C I R C U I T B R E A K ERl N S P E C T / T E S T / R E M O V E / l N S T A L L C I R C U I T B R E A K E R ( C O N T )l N S P E C T / T E S T / R E M O V E / l N S T A L L R E S E T C I R C U I T B R E A K ERl N S P E C T / T E S T / R E M O V E / l N S T A L L R E S E T C I R C U I T B R E A K E R ( C O N T)I N S P E C T C O N T R O L B O X W I R I N G H A R N E SSREPAIR CONTROL BOX HARNESS PLUGREPAIR CONTROL BOX HARNESS PLUG (CONT) - TM-5-4520-253-13_75REPAIR CONTROL BOX HARNESS PLUG (CONT) - TM-5-4520-253-13_76REPAIR WIRE TERMINALSR E P A I R W I R E T E R M I N A L S ( C O N T)REPLACE CONTROL BOX HARNESS WIRESREPLACE CONTROL BOX HARNESS WIRES (CONT) - TM-5-4520-253-13_80REPLACE CONTROL BOX HARNESS WIRES (CONT) - TM-5-4520-253-13_81REPLACE CONTROL BOX HARNESS WIRES (CONT) - TM-5-4520-253-13_82l N S P E C T / T E S T / R E M O V E / l N S T A L L H E A T E R - O F F - F A N S W I T CHl N S P E C T / T E S T / R E M O V E / l N S T A L L H E A T E R - O F F - F A N S W I T C H ( C O N T)l N S P E C T / T E S T / R E M O V E / l N S T A L L H E A T E R - O F F - F A N S W I T C H ( C O N T)R E M O V E / l N S T A L L H E A T A N D F A U L T L I G H TSREMOVE/lNSTALL HEAT AND FAULT LIGHTS (CONT)l N S P E C T / R E M O V E / l N S T A L L P O W E R R E C E P T A C L E A N D E X T E R N A L F U EL P U M P R E C E P T A C LElNSPECT/REMOVE/INSTALL POWER RECEPTACLE AND EXTERNAL FUEL PUMP RECEPTACLE (CONT)lNSPECT/REMOVE/lNSTALL POWER RECEPTACLE AND EXTERNAL FUEL PUMP RECEPTACLE (CONT) - TM-5-4520-253-13_90lNSPECT/REMOVE/lNSTALL POWER RECEPTACLE AND EXTERNAL FUEL PUMP RECEPTACLE (CONT) - TM-5-4520-253-13_91lNSPECT/REMOVE/lNSTALL POWER RECEPTACLE AND EXTERNAL FUEL PUMP RECEPTACLE (CONT) - TM-5-4520-253-13_92INSPECT PRINTED CIRCUIT (PC) BOARD ASSEMBLYHEATER CASE ASSEMBLY PROCEDURES INDEXl N S P E C T / S E R V I C E H E A T E R C A S E A S S E M B L Y ( C O N T )l N S P E C T / S E R V I C E H E A T E R C A S E A S S E M B L Y ( C O N T )l N S P E C T / S E R V I C E H E A T E R C A S E A S S E M B L Y ( C O N T )l N S P E C T / S E R V I C E H E A T E R C A S E A S S E M B L Y ( C O N T )l N S P E C T / S E R V I C E H E A T E R C A S E A S S E M B L Y ( C O N T )A D J U S T / l N S P E C T / S E R V I C E / R E M O V E / l N S T A L L S I D E P A N E L S A ND LOUVER LINKAGE (CONT]A D J U S T / l N S P E C T / S E R V I C E / R E M O V E / l N S T A L L S I D E P A N E L S A ND LOUVER LINKAGE (CONT]A D J U S T / l N S P E C T / S E R V I C E / R E M O V E / l N S T A L L S I D E P A N E L S A ND LOUVER LINKAGE (CONT]A D J U S T / l N S P E C T / S E R V I C E / R E M O V E / l N S T A L L S I D E P A N E L S A ND LOUVER LINKAGE (CONT]A D J U S T / l N S P E C T / S E R V I C E / R E M O V E / l N S T A L L D O O R S A N D B O T T O M C O V E R\A D J U S T / I N S P E C T / S E R V I C E / R E M O V E / l N S T A L L D O O R S A N D B O T T O M C O V E R ( C O N T)ADJUST/lNSPECT/SERVICE/REMOVE/lNSTALL DOORS AND B O T T O M C O V E R ( C O N T) - TM-5-4520-253-13_106ADJUST/lNSPECT/SERVICE/REMOVE/lNSTALL DOORS AND B O T T O M C O V E R ( C O N T) - TM-5-4520-253-13_107l N S P E C T / R E M O V E / l N S T A L L D A T A P L A T E Sl N S P E C T / R E M O V E / l N S T A L L D A T A P L A T E S ( C O N T )l N S P E C T / R E M O V E / l N S T A L L D A T A P L A T E S ( C O N T)l N S P E C T / R E M O V E / l N S T A L L D A T A P L A T E S ( C O N T)l N S P E C T / R E M O V E / l N S T A L L L A B E L SFUEL SYSTEM PROCEDURES INDEXl N S P E C T / R E P A I R / R E M O V E / 2. 3. 4. 5. INSTALL FUEL LINES AND FITTINGS (CONT)l N S P E C T / R E P A I R / R E M O V E / l N S T A L L F U E L L I N E S A N D F I T T I N G S ( C O N T )l N S P E C T / R E P A I R / R E M O V E / l N S T A L L F U E L L I N E S A N D F I T T I N G S ( C O N T )SERVICE/REMOVE/lNSTALL FUEL FILTERS E R V I C E / R E M O V E / l N S T A L L F U E L F I L T E R ( C O N T)S E R V I C E / R E M O V E / l N S T A L L F U E L F I L T E R ( C O N T)lNSPECT/SERVICE/ADJUST/REMOVE/lNSTALL CARBURETORlNSPECT/SERVICE/ADJUST/REMOVE/lNSTALL CARBURETOR CONT - TM-5-4520-253-13_121lNSPECT/SERVICE/ADJUST/REMOVE/lNSTALL CARBURETOR CONT - TM-5-4520-253-13_122lNSPECT/SERVICE/ADJUST/REMOVE/lNSTALL CARBURETOR CONT - TM-5-4520-253-13_123lNSPECT/SERVICE/ADJUST/REMOVE/lNSTALL CARBURETOR CONT - TM-5-4520-253-13_124l N S P E C T / T E S T / R E M O V E / l N S T A L L S O L E N O IDl N S P E C T / T E S T / R E M O V E / l N S T A L L S O L E N O I D ( C O N T )l N S P E C T / T E S T / R E M O V E / l N S T A L L S O L E N O I D ( C O N T ) ELECTRICAL PROCEDURES INDEX - TM-5-4520-253-13_128I N S P E C T C O M B U S T I O N B L O W E R ( C O N T)I N S P E C T V E N T I L A T I N G A I R M O T ORI N S P E C T V E N T I L A T I N G A I R M O T O R ( C O N T) - TM-5-4520-253-13_131I N S P E C T V E N T I L A T I N G A I R M O T O R ( C O N T) - TM-5-4520-253-13_132l N S P E C T / T E S T / R E M O V E / l N S T A L L S A F E T Y T H E R M O S T A T S A N D F L A ME S W I T C H A N D B R A C K E T A S S E M B LYl N S P E C T / T E S T / R E M O V E / l N S T A L L S A F E T Y T H E R M O S T A T S A N D F L A M E S W I T C H A N D B R A C K E T A S S E M B L Y ( C O N T )l N S P E C T / T E S T / R E M O V E / l N S T A L L S A F E T Y T H E R M O S T A T S A N D F L A M E S W I T C H A N D B R A C K E T A S S E M B L Y ( C O N T )l N S P E C T / T E S T / R E M O V E / l N S T A L L S A F E T Y T H E R M O S T A T S A N D F L A M E S W I T C H A N D B R A C K E T A S S E M B L Y ( C O N T )l N S P E C T / T E S T / R E M O V E / l N S T A L L S A F E T Y T H E R M O S T A T S A N D F L A M E S W I T C H A N D B R A C K E T A S S E M B L Y ( C O N T )BURNER ASSEMBLY PROCEDURES INDEXR E M O V E / l N S T A L L / T E S T / R E P A I R I G N I T I O N T R A N S F O R M E R A N D C A B L E ( C O N T)REMOVE/lNSTALL/TEST/REPAIR IGNITION TRANSFORMER AND CABLE (CONT) - TM-5-4520-253-13_140REMOVE/lNSTALL/TEST/REPAIR IGNITION TRANSFORMER AND CABLE (CONT) - TM-5-4520-253-13_141REMOVE/lNSTALL/TEST/REPAIR IGNITION TRANSFORMER AND CABLE (CONT) - TM-5-4520-253-13_142REMOVE/lNSTALL/TEST/REPAIR IGNITION TRANSFORMER AND CABLE (CONT) - TM-5-4520-253-13_143REMOVE/lNSTALL/TEST/REPAIR IGNITION TRANSFORMER AND CABLE (CONT) - TM-5-4520-253-13_144S E R V I C E / T E S T / R E M O V E / l N S T A L L I G N I T E R A S S E M B L YS E R V I C E / T E S T / R E M O V E / l N S T A L L I G N I T E R A S S E M B L Y ( C O N T)S E R V I C E / T E S T / R E M O V E / l N S T A L L I G N I T E R A S S E M B L Y ( C O N T)ACCESSORY ITEMS PROCEDURES INDEXT E S T / A D J U S T / R E M O V E / l N S T A L L R O O M T H E R M O S T A T ( C O N T)T E S T / A D J U S T / R E M O V E / l N S T A L L R O O M T H E R M O S T A T ( C O N T)R E M O V E / l N S T A L L S I D E H E A T E R C A S E C O V E RSR E N I O V E / l N S T A L L P O W E R , F U E L P U M P , A N D R O O M T H E R M O S T A T P L U GSR E M O V E / l N S T A L L P O W E R , F U E L P U M P , A N D R O O M T H E R M O S T AT PLUGS (CONT)R E M O V E / l N S T A L L P O W E R , F U E L P U M P , A N D R O O M T H E R M O S T AT PLUGS (CONT)P R E P A R A T I ONP A C K A G I N G C H A P T E R 4 I N T E R M E D I A T E M A I N T E N A N C E I N S T R U C T I O NSTable 4-1. Intermediate Maintenance TroubleshootingTable 4-1. Intermediate Maintenance Troubleshooting Continued - TM-5-4520-253-13_159Table 4-1. Intermediate Maintenance Troubleshooting Continued - TM-5-4520-253-13_160Table 4-1. Intermediate Maintenance Troubleshooting Continued - TM-5-4520-253-13_161Table 4-1. Intermediate Maintenance Troubleshooting Continued - TM-5-4520-253-13_162Table 4-1. Intermediate Maintenance Troubleshooting Continued - TM-5-4520-253-13_163Table 4-1. Intermediate Maintenance Troubleshooting Continued - TM-5-4520-253-13_164Table 4-1. Intermediate Maintenance Troubleshooting Continued - TM-5-4520-253-13_165Table 4-1. Intermediate Maintenance Troubleshooting Continued - TM-5-4520-253-13_166Section II. MAINTENANCE PROCEDURESPRINTED CIRCUIT (PC) BOARD ASSEMBLY PROCEDURES INDEXREMOVE/INSTALL PC BOARD ASSEMBLY (CONT)REMOVE/INSTALL PC BOARD ASSEMBLY (CONT) - TM-5-4520-253-13_170REMOVE/INSTALL PC BOARD ASSEMBLY (CONT)\REMOVE/INSTALL PC BOARD ASSEMBLY (CONT) - TM-5-4520-253-13_172REMOVE/INSTALL PC BOARD ASSEMBLY (CONT) - TM-5-4520-253-13_173REMOVE/INSTALL PC BOARD ASSEMBLY (CONT) - TM-5-4520-253-13_174REMOVE/INSTALL PC BOARD ASSEMBLY (CONT) - TM-5-4520-253-13_175REMOVE/INSTALL PC BOARD ASSEMBLY (CONT) - TM-5-4520-253-13_176REMOVE/INSTALL PC BOARD ASSEMBLY (CONT) - TM-5-4520-253-13_177REMOVE/INSTALL PC BOARD ASSEMBLY (CONT) - TM-5-4520-253-13_178R E P A I R P C B O A R D A S S E M B L Y W I R I N G R E C E P T A C LEREPAIR PC BOARD ASSEMBLY WIRING RECEPTACLE (CONT) - TM-5-4520-253-13_180REPAIR PC BOARD ASSEMBLY WIRING RECEPTACLE (CONT) - TM-5-4520-253-13_181R E P A I R P C B O A R D A S S E M B L Y W I R I N G T E R M I N A LSREPAIR PC BOARD ASSEMBLY WIRING 5. 6. TERMINALS (CONT) - TM-5-4520-253-13_183REPAIR PC BOARD ASSEMBLY WIRING 5. 6. TERMINALS (CONT) - TM-5-4520-253-13_184REPAIR PC BOARD ASSEMBLY HARNESS RECEPTACLE AND PLUGREPAIR PC BOARD ASSEMBLY HARNESS RECEPTACLE AND PLUG (CONT) - TM-5-4520-253-13_186REPAIR PC BOARD ASSEMBLY HARNESS RECEPTACLE AND PLUG (CONT) - TM-5-4520-253-13_187TEST PC BOARD A S S E M B L YTEST PC BOARD ASSEMBLY (CONT) - TM-5-4520-253-13_189TEST PC BOARD ASSEMBLY (CONT) - TM-5-4520-253-13_190TEST PC BOARD ASSEMBLY (CONT) - TM-5-4520-253-13_191TEST PC BOARD ASSEMBLY (CONT) - TM-5-4520-253-13_192TEST PC BOARD ASSEMBLY (CONT) - TM-5-4520-253-13_193TEST PC BOARD ASSEMBLY (CONT) - TM-5-4520-253-13_194TEST PC BOARD ASSEMBLY (CONT) - TM-5-4520-253-13_195HEATER CASE ASSEMBLY REPAIR PROCEDURES INDEXDISASSEMBLE/ASSEMBLE HEATER CASE ASSEMBLY (CONT)G E N E R A L R E P A I R H E A T E R C A S E A S S E M B LYGENERAL REPAIR HEATER CASE ASSEMBLY (CONT)REMOVE/lNSTALL SHIELDS AND SHIELD INSULATORREMOVE/lNSTALL SHIELDS AND SHIELD INSULATOR (CONT)R E P A I R P A I N T E D S U R F A C ESELECTRICAL PROCEDURES INDEX - TM-5-4520-253-13_203R E M O V E / I N S T A LL TM 5-4520-253-13 C O M B U S T I O N B L O W E R A N D H O U S I N G ( C O N T)R E M O V E / l N S T A L L C O M B U S T I O N B L O W E R A N D H O U S I N G ( C O N T)R E M O V E / I N S T A L L C O M B U S T I O N B L O W E R A N D H O U S I N G ( C O N T)REMOVE/lNSTALL/TEST THERMAL MOTOR PROTECTORREMOVE/lNSTALL/TEST THERMAL MOTOR PROTECTOR CONT.REMOVE/lNSTALL/TEST CAPACITORSDISASSEMBLE/ASSEMBLE/TEST BLOWER MOTORDISASSEMBLE/ASSEMBLE/TEST BLOWER MOTOR (CONT) - TM-5-4520-253-13_211DISASSEMBLE/ASSEMBLE/TEST BLOWER MOTOR (CONT) - TM-5-4520-253-13_212DISASSEMBLE/ASSEMBLE/TEST BLOWER MOTOR (CONT) - TM-5-4520-253-13_213R E P A I R B L O W E R M O T ORR E P A I R B L O W E R M O T O R ( C O N T)R E M O V E / l N S T A L L V E N T I L A T I N G A I R M O T O RREMOVE/lNSTALL VENTILATING AIR MOTOR (CONT) - TM-5-4520-253-13_217REMOVE/lNSTALL VENTILATING AIR MOTOR (CONT) - TM-5-4520-253-13_218REMOVE/lNSTALL VENTILATING AIR MOTOR (CONT) - TM-5-4520-253-13_219R E M O V E / l N S T A L L V E N T I L A T I N G A I R M O T O R ( C O N T)T E S T V E N T I L A T I N G A I R M O T ORTEST VENTILATING AIR MOTOR (CONT)T E S T V E N T I L A T I N G A I R M O T O R C A P A C I T O RT E S T V E N T I L A T I N G A I R M O T O R C A P A C I T O R ( C O N T)BURNER HEAD ASSEMBLY PROCEDURES INDEXREMOVE/lNSTALL BURNER HEAD ASSEMBLY (CONT) - TM-5-4520-253-13_226REMOVE/lNSTALL BURNER HEAD ASSEMBLY (CONT) - TM-5-4520-253-13_227R E P A IR TOOLS: B U R N E R H E A D A S S E M B LYREPAIR BURNER HEAD ASSEMBLY (CONT)HEAT EXCHANGER PROCEDURES INDEXREMOVE/lNSTALL HEAT EXCHANGER (CONT) - TM-5-4520-253-13_231REMOVE/lNSTALL HEAT EXCHANGER (CONT)REMOVE/lNSTALL HEAT EXCHANGER (CONT) - TM-5-4520-253-13_233REMOVE/lNSTALL HEAT EXCHANGER (CONT) - TM-5-4520-253-13_234CLEAN/lNSPECT/REPAIR HEAT EXCHANGERCLEAN/lNSPECT/REPAIR HEAT EXCHANGER (CONT)A P P E N D I X A R E F E R E N C ESA P P E N D I X B MAINTENANCE ALLOCATION CHARTUSE OF THE MAINTENANCE ALLOCATION CHART, SECTION IIEXPLANATION OF COLUMNS IN THE MAC, SECTION IIEXPLANATION OF COLUMNS IN THE MAC, SECTION IllSection Il. MAINTENANCE ALLOCATION CHART Continued - TM-5-4520-253-13_242Section Il. MAINTENANCE ALLOCATION CHART Continued - TM-5-4520-253-13_243Section Il. MAINTENANCE ALLOCATION CHART Continued - TM-5-4520-253-13_244Section Ill. TOOL AND TEST EQUIPMENT REQUIREMENTSA P P E N D I X C C O M P O N E N T S O F E N D I T E M S A N D B A S I C I S S U E I T E M S L I STSection Il. INTEGRAL COMPONENTS OF END ITEMSection Ill. BASIC ISSUE ITEMSA P P E N D I X D ADDITIONAL AUTHORIZATION LISTSection Il. ADDITIONAL AUTHORIZATION LISTA P P E N D I X E EXPENDABLE SUPPLIES AND MATERIALS LISTSection Il. EXPENDABLE SUPPLIES AND MATERIALS LIST - TM-5-4520-253-13_252A P P E N D I X F ILLUSTRATED LIST OF MANUFACTURED ITEMSFigure 3. Wire No. 10795Figure 5. Wire No. 10736Figure 7. Wire No. 10781Figure 9. Wire No. 10766Figure 11. Wire No. 10739.PART NUMBER INDEXA P P E N D I X G TORQUE LIMITSG L O S S A RYG L O S S A RY CONT.G L O S S A RY CONT. - TM-5-4520-253-13_263G L O S S A RY CONT. - TM-5-4520-253-13_264ALPHABETICAL INDEXALPHABETICAL INDEX CONT.ALPHABETICAL INDEX CONT.