JLG 120HX Service And Maintenance Manual Download Page 101

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SECTION 3 - TROUBLESHOOTING

3120686

– JLG Lift –

3-19

Damaged wiring on control switch or auxiliary
pump.

See proper wiring diagram.

Control switch not functioning properly.

Replace switch.

Restricted or broken hydraulic line or fitting.

Clean, repair or replace line or fitting.

Pump motor solenoid not functioning properly.

Replace solenoid.

Pump motor not functioning properly.

Repair or replace motor.

Table 3-5.Hydraulic System - Troubleshooting

TROUBLE

PROBABLE CAUSE

REMEDY

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Summary of Contents for 120HX

Page 1: ...Service and Maintenance Manual Model 120HX 3120686 May 15 2002 ANSI View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specifications on FreeCraneSpecs com...

Page 2: ...View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specifications on FreeCraneSpecs com...

Page 3: ...h potentially dangerous pressures Every effort should be made to relieve any system pres sure prior to disconnecting or removing any portion of the system Relieve system pressure by cycling the applic...

Page 4: ...ON LOG July 1 1992 Original Issue June 1 1995 Revised January 1999 Revised August 9 2001 Revised May 15 2002 Revised View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Cran...

Page 5: ...s 4 Wheel Steer 1 2 Platform Capacity 1 2 Boom Elevation 1 2 Machine Weight 1 2 Maximum Tire Load 1 2 Machine Height Stowed 1 2 Machine Length Stowed 1 2 Machine Width 1 2 Wheelbase 1 2 1 4 Function S...

Page 6: ...on 2 2 Battery 2 2 Lubrication and Servicing 2 2 2 3 Lubrication Information 2 2 Hydraulic System 2 2 Hydraulic Oil 2 3 Changing Hydraulic Oil 2 3 Lubrication Specifications 2 3 2 4 Cylinders Theory o...

Page 7: ...tz Engine 2 25 2 16 Pressure Setting Procedures 2 25 Main Valve 2 25 Frame Valve 2 27 2 17 Swing Bearing 2 32 Turntable Bearing Mounting Bolt Condition Check 2 32 Wear Tolerance 2 33 Replacement 2 33...

Page 8: ...ions 1 10 2 1 Boom Chain Adjustments 2 5 2 2 Typical Boom Assembly 2 6 2 3 Cylinder Barrel Support 2 14 2 4 Cylinder Rod Support 2 14 2 5 Poly Pak Seal Installation 2 15 2 6 Boom Assembly Sheet 1 of 2...

Page 9: ...ti Viscosity Oil 1 5 1 4 Hydraulic Oil 1 5 1 5 Lubrication Specifications 1 5 1 6 Lubrication Chart 1 7 1 7 Major Component Weights 1 9 1 8 Cylinder Specifications 1 9 1 9 Critical Stability Weights 1...

Page 10: ...JLG Lift 3120686 TABLE OF CONTENTS Continued This page left blank intentionally View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specifications on FreeCraneSpecs c...

Page 11: ...7 bar Drive Motor 2 speed 0 4 in 3 rev 6 4 cm 3 rev low speed 0 2 in 3 rev 2 5 cm 3 rev high speed Swing System Swing Motor Displacement 2 0 in 3 rev 32 8 cm 3 rev Swing Brake Automatic spring applie...

Page 12: ...use 52 ft 4 in 15 9 m Boom stowed for shipping 35 ft 10 5 8 in 10 9 m Machine Width 8 ft 6 in 2 6 m w axles retracted 10 ft 10 in 3 3 m w axles extended Wheelbase 11 ft 4 1 2 in 3 5 m 1 4 FUNCTION SP...

Page 13: ...o the Torque Chart Figure 1 1 to determine proper torque value Table 1 1 Torque Requirements Description Torque Value Dry Interval Hours Bearing To Chassis 220 FT LB 298 NM 200 500 Bearing To Turntabl...

Page 14: ...SECTION 1 SPECIFICATIONS 1 4 JLG Lift 3120686 Figure 1 1 Torque Chart View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specifications on FreeCraneSpecs com...

Page 15: ...cations NOTE Refer to Figure 1 2 for specific lubrication proce dures Table 1 2 Single Viscosity Oil When Outside Temperature is Consistently UseSAEViscosity Number 20 F to 25 F 29 C to 4 C 10W 15 F t...

Page 16: ...SECTION 1 SPECIFICATIONS 1 6 JLG Lift 3120686 Figure 1 2 Lubrication Diagram View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specifications on FreeCraneSpecs com...

Page 17: ...ssureGun 150 13 Sheave Pin Fly Extend 1GreaseFitting MPG PressureGun 150 14 Sheave Pin Upper Aux 1GreaseFitting MPG PressureGun 150 15 Tele Cyl Sheave Pin 1GreaseFitting MPG PressureGun 150 Extendboom...

Page 18: ...access underturntable 27 Hydraulic Filter Function Pump N A N A 50 300 Replaceafterfirst50hrs of operation thenevery300hrs thereafter 28 Hydraulic Filter Drive Pump N A N A 50 300 Replaceafterfirst50h...

Page 19: ...nsions are given in inches in with the met ric equivalent centimeters cm given in parenthe ses Table 1 7 Major Component Weights COMPONENT LB KG Platform 36 x 72 in 0 9 x 1 8 m w Control Box Sup port...

Page 20: ...T OR SPECIFICATION DO NOT MODIFY UNIT IN ANY WAY TO AFFECT STABILITY Table 1 9 Critical Stability Weights COMPONENT WEIGHT Counterweight 9 050 lb 4 105 kg Foam Filled Tires each 932 lb 423 kg Deutz En...

Page 21: ...fuel or oil lines are discon nected clear adjacent areas as well as the openings and fittings themselves As soon as a line or compo nent is disconnected cap or cover all openings to prevent entry of f...

Page 22: ...manual at the specified intervals When recommended lubricants are not available consult your local supplier for an equivalent that meets or exceeds the specifications listed Battery Clean battery usin...

Page 23: ...rers are always the best choice however multi purpose greases usually have the qualities which meet a variety of single purpose grease requirements Should any question arise regarding the use of greas...

Page 24: ...r than the load requirement with the valve diverting excess pump delivery back to the reservoir when operating pres sure of the component is reached Crossover Relief Valves Crossover relief valves are...

Page 25: ...SECTION 2 PROCEDURES 3120686 JLG Lift 2 5 Figure 2 1 Boom Chain Adjustments View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specifications on FreeCraneSpecs com...

Page 26: ...S INJURY OR DEATH TO PERSONNEL OPERATING THE JLG BOOM LIFT Inspection Procedure BOOM CHAINS TO BE INSPECTED AT TIME OF NEXT BOOM OVERHAUL AND WHEN DEEMED NECESSARY BY MACHINE OWNER BUT NOT TO EXCEED 2...

Page 27: ...the rated lifting capacity of these chains e Tight Joints All joints in the roller chain should flex freely On roller chain tight joints are usually caused by rust corrosion or the inside plates walki...

Page 28: ...BELOW BOOM AND PLATFORM AND AHEAD OF PLATFORM ARE CLEAR OF ALL OBSTRUCTIONS AND PER SONNEL 2 Position LIFT control switch to UP and hold until boom reaches horizontal 3 Position TELESCOPE control swit...

Page 29: ...is leaking from the counterbalance valve the valve is either improperly adjusted or defective and requires replacement ENSURE THAT HYDRAULIC LINES ARE CONNECTED AS MARKED PRIOR TO BEING DISCONNECTED 9...

Page 30: ...c system and run cylinder through one complete cycle to check for leaks Cylinders w Dual Counterbalance Valve Axle Extension Cylinders Telescope Cylinder Platform Slave Level Cylinder OPERATE ALL FUNC...

Page 31: ...bolts washers and lockwash ers attaching the chain adjust bracket to the aft end of the base boom and remove bracket 16 Pull boom sections apart several feet 17 Using the lifting equipment raise the...

Page 32: ...Place the machine on a flat and level surface Start the engine and place the boom in a horizontal posi tion Shut down the engine and attach a suitable support device to the boom 2 Tag disconnect and c...

Page 33: ...with retaining plate and retaining plate bolts 3 Remove caps from temporary hydraulic lines and attach to level cylinder ports Using auxiliary power activate swing function and extend cylinder rod un...

Page 34: ...a vise or similar holding fixture as close to the piston as possible 9 Remove the set screw s if applicable and nut which attach the piston to the rod and remove the piston Discard nylon point set scr...

Page 35: ...ce as necessary Assembly NOTE Prior to cylinder assembly ensure that the proper cylinder seal kit is used See your JLG Parts Manual NOTE Apply a light film of hydraulic oil to all components prior to...

Page 36: ...USE EITHER A TRAVELING OVERHEAD HOIST FORKLIFT OR OTHER MEANS TO SUPPORT THE OVERHANGING WEIGHT OF THE EXTENDING ROD NOTE Steps 17 through 20 apply to the telescope cylin der 17 Elevate the barrel end...

Page 37: ...bly HYDRAULIC LINES AND PORTS SHOULD BE CAPPED IMMEDI ATELY AFTER DISCONNECTING LINES TO AVOID ENTRY OF CONTAMINANTS INTO SYSTEM 2 Tag and disconnect hydraulic lines to slave level cyl inder and rotat...

Page 38: ...OCEDURES 2 18 JLG Lift 3120686 17 14 5 12 16 16 16 6 Figure 2 6 Boom Assembly Sheet 1 of 2 View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specifications on FreeCr...

Page 39: ...ly Retract Chain 9 Outer Mid Retract Chain 10 Tele Cylinder Sheave 11 Sheave 12 Chain Extend Rod 13 Chain Attach Pin 14 Chain Adjustment Assembly 15 Chain Adjustment Assembly 16 Upper Rear Wear Pad 17...

Page 40: ...o chain will become accessible Remove cotter pins and clevis pin attaching exten sion bar to chain and remove bar 33 Carefully lift telescope cylinder clear of boom assembly and lower to ground or sui...

Page 41: ...ge Replace boom sections as necessary Assembly NOTE When installing fly section wear pads install same number and thickness of shims as were removed during disassembly 1 Install upper aft fly section...

Page 42: ...nner mid sec tion Tie chains to underside of inner mid section using suitable straps 31 Using suitable lifting equipment carefully align holes in telescope cylinder trunnion and holes in aft end of in...

Page 43: ...ing bolts washers and lockwashers 7 Shut down machine systems 8 Connect hydraulic lines running along side of boom 9 Install boom length angle sensor box Adjust boom length angle sensor box in accorda...

Page 44: ...e of the indicator by tightening the three flange nuts Tighten each nut through approxi mately one half of it s spring s travel DO NOT ADJUST THE X NUT DURING THE REMAINDER OF THE PROCEDURE 3 With the...

Page 45: ...ver making sure that low mid engine setting remains the same If necessary adjust slide pin to contact low mid engine limit switch at 1800 RPM Shut down engine 2 Start the engine from ground controls a...

Page 46: ...SWITCH SLIDE PIN 2 SLIDE PIN 1 LIMIT SWITCH THROTTLE LEVER THROTTLE LEVER STOP INJECTION PUMP ACTUATOR CABLE ADECO ACTUATOR Figure 2 10 Throttle Checks and Adjustments Deutz Engine View thousands of C...

Page 47: ...teer pressure a Plug pressure gauge into quick connection on frame valve Monitor gauge b Bottom out Front Steer Right function c Loosen nut on front steer right relief and adjust to 2000 psi 138 bar T...

Page 48: ...8 JLG Lift 3120686 Figure 2 11 Pressure Setting Adjustments Main Valve Machines Built Before S N 38697 View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specificatio...

Page 49: ...686 JLG Lift 2 29 Figure 2 12 Pressure Setting Adjustments Frame Valve Machines Built Before S N 38697 View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specificatio...

Page 50: ...0 JLG Lift 3120686 Figure 2 13 Pressure Setting Adjustments Main Valve Machines Built After S N 38697 View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specification...

Page 51: ...0686 JLG Lift 2 31 Figure 2 14 Pressure Setting Adjustments Frame Valve Machines Built After S N 38697 View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specificatio...

Page 52: ...eler Gauge Check try and insert the 0 0015 feeler gauge between the bolt head and hardened washer at the arrow indicated position 3 Assure that the 0 0015 feeler gauge will not pene trate under the bo...

Page 53: ...n shows no defects reassemble bearing and return to service THE SWING BEARING IS ONE OF THE MOST CRITICAL POINTS ON AN AERIAL LIFT IT IS HERE THAT THE STRESSES OF LIFT ING ARE CONCENTRATED AT THE CENT...

Page 54: ...Ensure that the scribed line of the outer race of the bearing aligns with the scribed mark on the frame if a new swing bearing is used ensure that the filler plug fitting is at 90 degrees from the fo...

Page 55: ...rol station use boom lift control to lower boom to stowed position m Using all applicable safety precautions activate hydraulic system and functionally check swing system for proper and safe operation...

Page 56: ...SECTION 2 PROCEDURES 2 36 JLG Lift 3120686 Figure 2 19 Drive Torque Hub View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specifications on FreeCraneSpecs com...

Page 57: ...ey can be driven out of hub counterbores Discard seal and replace with new seal EYE PROTECTION SHOULD BE WORN DURING RETAINING RING REMOVAL 13 To remove cluster gear 206 from carrier remove retaining...

Page 58: ...one thrust bearing 16 between two thrust washers 15 and place them onto spindle pilot EYE PROTECTION SHOULD BE WORN DURING RETAINING RING INSTALLATION 5 Install retaining ring 10 in groove of input s...

Page 59: ...ace of hub These holes have been coun terbored to accept four shoulder bolts upon installa tion of cover 14 Thrust spacer 14 input gear 13 and input spacer 12 are installed onto input shaft 11 Counter...

Page 60: ...shafts 15 from carrier 10 ensuring that nee dle rollers 13 on each shaft are not damaged or lost c Lift cluster gears 11 from carrier 10 and remove thrust washers 12 needle rollers 13 and roller spac...

Page 61: ...SECTION 2 PROCEDURES 3120686 JLG Lift 2 41 Figure 2 20 Swing Torque Hub View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specifications on FreeCraneSpecs com...

Page 62: ...ered portion of shaft hole upper most j Position new roll pin 16 in hole in carrier 10 and drive pin into hole until end of pin is flush with carrier surface k Repeat steps a through j for remaining t...

Page 63: ...of springs or spring pattern Record this information for assembly purposes Spring retainer 17 was not used in ear lier models 7 Remove dowel pins 20 springs 15 16 and spring retainer 17 from housing...

Page 64: ...SECTION 2 PROCEDURES 2 44 JLG Lift 3120686 Figure 2 21 Swing Brake View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specifications on FreeCraneSpecs com...

Page 65: ...E COVER CAN BE HELD IN POSITION WHILE REMOVING THE WASHER HEAD CAP SCREWS 2 Remove case seal 11 from housing then remove bleeder screw 14 o ring 28 and gasket 29 from end cover 3 Remove piston 24 from...

Page 66: ...SECTION 2 PROCEDURES 2 46 JLG Lift 3120686 Figure 2 22 Drive Brake Mico View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specifications on FreeCraneSpecs com...

Page 67: ...ng 26 in end cover 12 Position end cover on housing aligning dowel pins with holes in end cover 13 Install washer head bolts 12 and tighten evenly to draw end cover to housing Torque washer head bolts...

Page 68: ...e within toler ance proceed to step 12 9 If the readings in step 9 were not within tolerance Loosen the setscrew located in the gear on the potentiometer shaft of the controller Using a screw driver a...

Page 69: ...can be achieved without further trimpot adjustments 20 Adjust the Ramp trimpot 6 turns clockwise 21 Release footswitch 22 Connect ORANGE RED dump wire to terminal strip number 3 in platform console 2...

Page 70: ...N 38697 to Present for mid 17 Move controller handle back to the position given in step 6 and check ammeter reading This reading will have changed due to HI trimpot adjustment and must be readjusted...

Page 71: ...achine f Seal ramp pot adjustment screw with a drop of enamel paint to prevent maladjustment due to vibration g Install controller and secure machine 2 Swing Controller a Using all applicable safety p...

Page 72: ...onnector pins 1 and 4 on plug 2 on the circuit card c Rotate the 5K Ohm potentiometer until 100 Ohms is measured between Pin 1 and Pin 4 on the 6 pin plug connector which mates with J2 d Tighten the t...

Page 73: ...age at TP3 Adjust R1 until 8 0 Volts is obtained 2 Measure voltage at TP1 Adjust R17 until 3 0 Volts is obtained 2 26 LOAD MANAGEMENT SYSTEM The LMS Load Management System consists of three independen...

Page 74: ...es output dc voltage when the boom is within a predetermined critical boom length This signal energizes a 12 volt dc solenoid flow control valve via a relay in the overmoment control circuit card to e...

Page 75: ...independent 12 volt timer relays 1 second delay off relay B which control the output signals from both circuit cards If the input is removed the timer relay B will de energize after 1 second If an ou...

Page 76: ...JLG Lift 3120686 Figure 2 27 Boom Length Angle Sensor Configuration Figure 2 28 Load Radius Circuit Card View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specificat...

Page 77: ...686 JLG Lift 2 57 TEST SWITCH RESET SWITCH 2 Figure 2 26 Load Moment Limiting System Monitoring Circuit View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specificati...

Page 78: ...turntable which attach to the turntable spring bolts 4 If necessary remove the bolts which secure the load management switches to the mounting bracket and allow the switches to hang freely WRAP MASKI...

Page 79: ...te annual inspection be performed in accordance with the Annual Machine Inspection Report form Forms are supplied with each new machine and are also available from JLG Customer Service Forms must be c...

Page 80: ...med every two years Table 2 7 Preventive Maintenance and Inspection Schedule AREA DAILY WEEKLY INTERVAL MONTHLY 3 MONTH 6 MONTH YEARLY BOOM 1 Platform 1 4 2 Platform Gate 1 4 12 3 Platform Rotator 5 1...

Page 81: ...ic Oil Tank 3 5 4 15 Breather Hydraulic Tank 6 14 16 Fuel Tank 3 5 4 17 Cylinders 1 5 6 13 4 12 19 Turntable Locking Pin 1 7 20 Horizontal Limit Switch 1 7 21 Oil Coupling 5 22 Placards and Decals 1 2...

Page 82: ...Steer Components 1 4 6 8 12 7 Tie Rod Lock Pin 1 8 8 Hydraulic Hoses 1 5 9 Placards and Decals 1 2 10 Wheel Bearings 8 12 11 Swing Bearing Worm Gear 12 9 Table 2 7 Preventive Maintenance and Inspecti...

Page 83: ...trical systems For this reason every effort has been made to ensure that all likely problems in these areas are given the fullest possible treatment In the remaining machine groups only those problems...

Page 84: ...edslavelevelormainliftcylinder Repairorreplacecylinder Noresponsetoplatformlevelingcontrols Levelfunctionnotactivatedwithin7seconds afterfootswitchwasdepressed Recyclefootswitch Levelcontrolswitchinop...

Page 85: ...ing Dirtorotherforeignmaterialunderseal Removeandrepairvalveasnecessary Valvespoolscored Removevalveandrepairorreplaceasneces sary Excessivebackpressurecausedbyrestricted returnlinetoreservoir Removel...

Page 86: ...notfunctioning Repairorreplacevalve Liftcylindernotfunctioningproperly Repairorreplacecylinder Bindingliftcylinderorboompivotpin Repairorreplacecylinderorpin Boomwillnotlower See Boomwillnotraise Pre...

Page 87: ...csystemoillow Replenishoilasnecessary Damagedwiringoncontrolswitchorsolenoid valve Repairorreplacewiring Controlvalvenotfunctioningproperly Repairorreplacevalve Restrictedorbrokensupplylineonvalvebank...

Page 88: ...ed Correctlyadjustcamvalves Defectivecylinderorbindingboom Repairorreplacecylinderordefectiveboom parts Towerliftcylinderwillnotlower Functionnotactivatedwithin7secondsafter footswitchwasdepressed Rec...

Page 89: ...rorreplacepressurereducingvalve Noelectricpowertovalve Seeproperwiringdiagram Boomwillswinginonedirectiononly Restrictedorbrokenhydrauliclineorfitting Clean repair orreplacelineorfitting Controlvalven...

Page 90: ...trictedorbrokenhydrauliclineorfitting Clean repair replacelineorfitting Holdingvalve s oncylinder s notworking Replaceholdingvalve s Controlvalvesnotfunctioningproperly Repairorreplacevalve Pressurere...

Page 91: ...3times Holdingvalvesontowerliftoruprightlevelcylin dercontaminated Determineandremedysourceofcontamination Replaceholdingvalve Reliefvalvesettoolowonlevelcircuit Correctlyadjustvalve Towerlevelmaster...

Page 92: ...Returnspringweakorbroken Removevalveandrepairorreplaceasneces sary Reliefvalvemalfunctioningcausingexcessive pressurewithinvalve Checkpressuredeliverytoandfromvalveand repairorreplaceasnecessary Valve...

Page 93: ...heckrelay Enginewillnotstart ignitionOK Nofuel Replenishfuelasnecessary Cloggedfuelfilter Replacefuelfilter Chokesolenoidmalfunction Replacechokesolenoid Restrictedorbrokenfuelline Cleanorreplacefuell...

Page 94: ...inkortierodbrokenorattachinghard waremissing Replacesteeringlink tierodorhardwareasnec essary Oneorbothfrontwheelswillnotrotateor rotateerratically Wheelhuborbearingsdamagedornotlubri cated Replacehub...

Page 95: ...replaceline Drivemotor s notfunctioningproperly Repairorreplacemotor s Airinwheelbrakecircuit Bleedcircuit determineandcorrectcause Fuseisblow outoncontrolcard Replacefuse Damagedwiringoncontrolswitch...

Page 96: ...esponse functionshutsoffslowly whencommandisremoved Lowspoolspringpreload Checkforcorrectspringandshimsinendcaps Stickingspoolduetocontamination Removeendcapandcheckspoolfreedom Rampsettoohighincontro...

Page 97: ...id valve Seeproperwiringdiagram Solenoidvalvenotfunctioningproperly Repairorreplacevalve Controlswitchnotfunctioningproperly Replaceswitch Reliefvalveimproperlysetornotfunctioning properly Reset repai...

Page 98: ...lacevalveasrequired Steerlinkagesloose Tightenlinkage Steerwheeltoe innotsetproperly Adjusttoe infor1 4inchoverall Spindlebushingsbadlyworn Replacebushings Table 3 4 Chassis Assembly Troubleshooting T...

Page 99: ...ation Restrictedsuctionline Clean repair orreplaceline Restrictedreservoirairvent Cleanorreplacevent Oilviscositytoohigh Drainsystemandreplacewithrecommendedoil RefertoHydraulicOils Airleakinsuctionsi...

Page 100: ...omponent lineorfitting Scoredvalvespool scoredcylinder Replacevalve replacecylinder Amperagetoolowoncontroller Correctlyadjustcontroller Lowsequencepressure Resetvalveasrequired Lowpilotpressure Reset...

Page 101: ...tedorbrokenhydrauliclineorfitting Clean repairorreplacelineorfitting Pumpmotorsolenoidnotfunctioningproperly Replacesolenoid Pumpmotornotfunctioningproperly Repairorreplacemotor Table 3 5 Hydraulic Sy...

Page 102: ...ingatestmeter checkrelaycoilterminalsfor presenceofelectricalpowerandforenergization ofrelaycoil Alsocheckrelayterminalsforcor rectswitchingofcontacts Replacerelayasnec essary Malfunctioningstartersol...

Page 103: ...Replacebulb Highenginespeedwillnotfunction Boomabovehorizontal Lowerboom Horizontallimitswitchmalfunctioning Repairorreplacelimitswitch Drivecontrollerdefective Replacecontroller Highenginesolenoidmal...

Page 104: ...ROUBLESHOOTING 3 22 JLG Lift 3120686 Figure 3 1 Electrical Diagram Boom Length Indicator View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specifications on FreeCran...

Page 105: ...3 TROUBLESHOOTING 3120686 JLG Lift 3 23 Figure 3 2 Electrical Schematic Sheet 1 of 4 View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specifications on FreeCraneSp...

Page 106: ...OUBLESHOOTING 3 24 JLG Lift 3120686 Figure 3 3 Electrical Schematic Sheet 2 of 4 1870023B View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specifications on FreeCra...

Page 107: ...3 TROUBLESHOOTING 3120686 JLG Lift 3 25 Figure 3 4 Electrical Schematic Sheet 3 of 4 View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specifications on FreeCraneSp...

Page 108: ...OUBLESHOOTING 3 26 JLG Lift 3120686 Figure 3 5 Electrical Schematic Sheet 4 of 4 1870023B View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specifications on FreeCra...

Page 109: ...3 TROUBLESHOOTING 3120686 JLG Lift 3 27 Figure 3 6 Hydraulic Schematic Sheet 1 of 2 View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specifications on FreeCraneSpe...

Page 110: ...ROUBLESHOOTING 3 28 JLG Lift 3120686 2792377A Figure 3 7 Hydraulic Schematic Sheet 2 of 2 View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specifications on FreeCra...

Page 111: ...View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specifications on FreeCraneSpecs com...

Page 112: ...View thousands of Crane Specifications on FreeCraneSpecs com View thousands of Crane Specifications on FreeCraneSpecs com...

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