Service Manual User Manual

SECTION 3 - TROUBLESHOOTING
3120696 – JLG Sizzor – 3-5
Loose or damaged wire between platform and
high speed solenoid
Ensure proper connection of wire at the platform
and at the high speed solenoid. Using suitable test
meter, perform continuity test on wire. repair or
replace harness as necessary.
High speed solenoid not functioning properly Replace e solenoid
Loose or damaged wires between high sped relay
and high speed limit switch
Ensure proper connection of wires between high
speed relay and high speed limit switch. Using
suitable test meter, perform continuity test on wire.
repair or replace harness as necessary.
High speed limit switch not functioning properly Repair or replace limit switch
Loose or damaged wire in valve wiring harness Ensure proper connection of wires at the terminal
strip. Using suitable test meter, perform continuity
test on wire. repair or replace harness as neces-
sary.
STEERING SYSTEM
No response to control
Enable switch not activated Activate enable switch
Function not activated within the 3 seconds after
enable switch was depressed
Reactivate enable switch
Enable switch not functioning properly Replace enable switch circuit card
Hydraulic system oil low Replenish oil as necessary
Damaged wiring on control switch or solenoid
valve
See proper wiring diagram
Controller not functioning properly Replace controller
Restricted or broken hydraulic line on valve bank
or hydraulic pump
Clean repair or replace line
Control valve not functioning properly Repair or replace valve
Steer cylinder not functioning properly Repair or replace steer cylinder
Machine hard to steer or steering is erratic
Hydraulic system oil low Replenish oil as necessary
Restricted hydraulic line or fitting Clean, repair or replace line or fitting
Lack of lubrication Lubricate as required (refer to lubrication chart)
Restricted crossover relief valve (pressure low) Clean or replace valve
Steer system pressure low Adjust pressure
Bent steering linkage Repair or replace linkage as required
Hydraulic pump not functioning properly Repair or replace pump
Steer cylinder not functioning properly Repair or replace cylinder
Tire pressure low Correct tire pressure
Bent or seized spindle Replace spindle
Steering inoperative
Damaged wiring on controller or solenoid valve See proper wiring diagram
Solenoid valve not functioning properly Repair or replace valve
Controller not functioning properly Replace controller
Relief valve improperly set or not functioning prop-
erly
Reset, repair or replace valves as required
Steer cylinder not functioning properly Repair or replace steer cylinder
Table 3-2. Chassis Troubleshooting
TROUBLE PROBABLE CAUSE REMEDY