JLG 3969electric ANSI Service Manual - Manual (Page 34)

SECTION 3 - TROUBLESHOOTING
3-4
– JLG Sizzor – 3120768
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 3 seconds after
enable switch was depressed Reactivate enable switch
Enable switch not functioning properly Replace enable switch circuit card
Drive motor(s) not functioning properly Repair or replace drive motors
Damaged wiring on hand controller See wiring schematic.repair or replace wiring as
necessary
Sevcon overheated Check flashcode
Defective hand controller Repair or replace hand controller
Damaged wiring on motor controller See wiring schematic. repair or replace wiring as
necessary
Defective enable switch Repair or replace enable switch
Defective motor controller Check flashcode. Replace motor controller
Defective motor controller contactors Repair or replace contactors
Low battery Check flashcode on sevcon
Machine will not travel forward Enable switch not activated Activate enable switch
Function not activated within 3 seconds after
enable switch was depressed Reactivate enable switch
Enable switch not functioning properly Replace enable switch circuit card
Drive motor(s) not functioning properly Repair or replace drive motors
Brake(s) not releasing Repair or replace electric brake
Motor/Pump will not respond when drive control
moved to forward Refer to electrical system troubleshooting
Motor controller forward contactor defective Repair or replace contactor
Machine will not travel in reverse Motor controller reverse contactor defective Repair or replace contactor
See machine will not travel forward
Machine travels very slow below horizontal Defective hand controller Check flashcode on Sevcon (6 flashes)
Sevon controller not programmed properly Reprogram Sevcon
Drive system very jerky Sevcon controller defective Check flashcode
Machine will speed up in forward or reverse Wires loose or broken from Tach Drive system to
Sevcon controller Check flashcode on Sevcon. Repair or replace wire
as necessary
Tach Drive shaft broke off Replace Tach Drive shaft
Tach Drive defective Check flashcode