JLG 26MRT Service & Maintenance page 48

SECTION 3 - TROUBLESHOOTING
TROUBLE
No response to drive controller
Machine drives erratically
Machine will not travel forward
Machine will not travel in reverse
3-4
Table 3-2. Chassis Troubleshooting
PROBABLE CAUSE
Drive System
Enable switch not activated. .
Controller not activated within three sec-
onds after enable switch is activated.
Enable circuit not functioning properly.
Hydraulic system oil low.
Hydraulic pump not functioning properly. Repair or replace pump.
Restricted or broken pump supply line.
Drive motor not functioning properly.
Damaged wiring on drive controller.
Drive controller not functioning properly.
Drive brake not releasing.
Microcircuit on controller improperly
adjusted.
Enable switch not activated.
Drive controller not activated within three
seconds after enable switch is activated.
Enable circuit not functioning properly.
Hydraulic system oil low.
Restricted or broken hydraulic line or fit-
ting.
Control valve not functioning properly.
Drive motor not functioning properly.
Brake not functioning properly.
Engine will not respond when enable
switch is activated and drive controller is
activated .
No electrical signal being sent to the drive
valve cartridge.
See: Machine will not travel forward.
– JLG Sizzor –
REMEDY
Activate enable switch
Activate enable switch, then activate drive
controller within three seconds.
Replace enable circuit card.
Replenish oil as necessary.
Clean, repair or replace line.
Repair or replace motor.
Repair or replace wiring.
Repair or replace controller.
Determine cause and repair or replace
brake.
Adjust microswitch on controller for
proper operation.
Activate enable switch.
Activate enable switch, then activate drive
controller within three seconds.
Replace enable circuit card.
Replenish oil as necessary.
Clean, repair or replace line or fitting.
Repair or replace valve.
Repair or replace motor.
Repair or replace brake.
Refer to Electrical System Troubleshoot-
ing - No response to control switch.
Refer to Electrical System Troubleshoot-
ing - No response to control switch.
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