JLG 25RTS, Service & Maintenance

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SECTION 3 - TROUBLESHOOTING
3-10 – JLG Sizzor – 3120826
Defective Platform/Ground select switch Replace Platform/Ground select switch
No voltage present at function control switch Check wiring from power switch to function control
switch for proper connection or damage. Repair or
replace wiring as necessary
Defective function control switch Replace function control switch
No voltage present at applicable control valve coil Check applicable wire for proper connection at
terminal strip, valve harness plug pin, valve har-
ness receptacle pin and valve coil. Using suitable
test meter, perform continuity test on wire. Repair
or replace harness as necessary
No voltage supplied to motor from start relay Check battery cable from relay to motor for proper
connection or damage. Repair or replace cable as
necessary
Defective motor/pump assembly Replace motor/pump assembly
ENGINE STARTER SYSTEM
Engine will not crank
Discharged battery or loose battery terminals Check and charge battery or replace battery as
necessary. Clean and secure battery terminals
Starter relay faulty or faulty relay connections Using a test meter, check relay coil terminals for
presence of electrical power and for energization
of relay coil. Also check relay terminals for correct
switching of contacts. Replace relay as necessary
Malfunctioning starter solenoid or motor Replace solenoid or motor in accordance with
applicable manufacturer’s manual
Defective start lockout solenoid Replace start lockout solenoid
Malfunctioning ignition switch Using a test meter, check ignition switch for cor-
rect switching of contacts. replace switch as nec-
essary
Faulty ignition and/or starter circuit wiring Check wiring continuity. refer to wiring diagram
Defective ring gear or flywheel Replace ring gear
INSTRUMENTS AND INDICATORS
Ammeter inoperative
Damaged wiring in circuits Repair or replace wiring
Ammeter not functioning properly Replace ammeter
Alternator not charging Repair or replace alternator
Travel warning horn inoperative
Circuit breaker open Determine and correct cause
Damaged wiring in horn circuit Replace horn
Hourmeter inoperative
Damaged wiring in hourmeter circuit Repair or replace wiring
Inoperative hourmeter Replace hourmeter
Table 3-5. Electrical System Troubleshooting
TROUBLE PROBABLE CAUSE REMEDY