JLG 3246E2 ANSI Service Manual - Manual (Page 70)

SECTION 3 - TROUBLESHOOTING
3-2 – JLG Lift – 3120737
Table 3-1. Electrical Troubleshooting Chart
TROUBLE PROBABLE CAUSE REMEDY
All machine functions do not operate
Emergency stop switch not activated Activate Emergency stop switch
Joystick not in neutral position Release joystick, then select function
Platform cable not connected to platform box
or at base
Re-connect cable to platform box and check
wiring at base
Battery voltage out of range
If battery cahrger is plugged in Check voltage with VOM. Unplug battery
charger
Battery voltage too low Check voltage with VOM. Plug in battery
charger
Line contactor open circuit
Loose wiring connections on line contactor or
at harness connection
Check wire terminations on line contactor
and harness connection at base. Tighten
connections as necessary
Open coil on line contactor Clean corrosion from line contactor
Replace line contactor
Faulty wiring at base Repair or replace wiring as necessary
Line contactor welded. Replace the line contactor
Line contactor or other driver short circuit or
tripped
Point A short circuit
Motor stalled Determine cause. Repair or replace motor as
necessary
Motor open circuit
Faulty motor Replace motor
No drive function when platform fully low-
ered. Lift function okay
Malfunctioning limit switch Use VOM to verify limit switch inputs. Adjust
or repair malfunctioing limit switch
No drive function when platform elevated.
Lift function okay
Malfunctioning limit switch Use VOM to verify limit switch inputs. Adjust
or repair malfunctioing limit switch
Platform above drive cutout height Lower platform below drive cutout height
Machine cannot lift down. Lift up function
okay
Loose wiring on lift cylinder (s) at holding
valve
Repair wiring on lift cylinder (s) at holding
valve