JLG 40RTS Service Manual - Manual (Page 68)

SECTION 3 - TROUBLESHOOTING
3-4 – JLG Sizzor – 3120826
Table 3-2. Chassis Troubleshooting
TROUBLE PROBABLE CAUSE REMEDY
DRIVE 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
Drive hubs disengaged Engage hubs
Controller not properly adjusted Correctly adjust controller
Hydraulic pump not functioning properly Repair or replace pump
Restricted or broken pump supply line Clean, repair or replace line
Restricted or broken line on valve bank Clean, repair or replace line
Drive motor(s) not functioning properly Repair or replace motor(s)
Damaged wiring on controller Repair or replace wiring
Controller not functioning properly Repair or replace controller
Drive brake not releasing Determine cause and repair or replace brake
Machine drives erratically
Microswitch on controller improperly adjusted Adjust microswitch on controller for proper opera-
tion
Machine will not travel forward
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
Restricted or broken hydraulic line or fitting Clean, repair or replace line or fitting
Controller not adjusted properly Correctly adjust controller
Control valve not functioning properly Repair or replace valve
Drive motor(s) not functioning properly Repair or replace motor(s)
Defective controller Repair or replace controller
Machine will not travel in reverse
See: Machine will not travel forward
High speed function does not operate
Loose or damaged wiring between controller and
high speed switch Ensure proper connection of wires. Using suitable
test meter, perform continuity test on wiring
between controller and switches. Repair or
replace wires as necessary.
Defective high speed control switch Replace switch
Loose or damaged wire in control box wire har-
ness Ensure proper connection of wire at the control
switch. Using suitable test meter, perform continu-
ity test on wire. repair or replace harness as neces-
sary.