JLG 3969electric ANSI Service Manual - Manual (Page 37)

SECTION 3 - TROUBLESHOOTING
3120768 – JLGSizzor –
3-7
Table 3-4. Electrical System Troubleshooting
TROUBLE PROBABLE CAUSE REMEDY
ELECTRICAL SYSTEM
Hand controller No electric power to hand controller Check electrical input to hand controller
Control valve will not function when thumb-
switch is moved in either direction No electric power to valve Check electric output and electrical signal at the
valve
Improper ground Check for proper grounding
No response to a function control switch Emergency stop switch no positioned properly Place emergency stop switch to on position
Platform/Ground select switch not positioned
properly Place Platform/Ground select switch to proper
position
Batteries defective or require charging Check batteries for serviceability. Replace or
charge batteries as necessary
No voltage supplied to drive motors Check motor controller and contactors for
proper functioning. Repair or replace as neces-
sary
Defective function switch Replace switch
Defective circuit breaker Replace circuit breaker
No voltage present at applicable control valve Check applicable wire for proper connection.
Using suitable test meter, perform continuity test
on wire. Repair or replace wire as necessary
Defective motor/pump assembly Replace motor/pump assembly
Drive motors will not function when hand
controller is activated Motor controller 200 Amp fuse blown Check flashcode on Sevcon and determine
cause and repair. Replace fuse
Hydraulic pump/motor will not run Batteries require charging or will not charge Charge or replace batteries as required
Motor controller contactors not functioning prop-
erly Repair or replace contactors
Pump/motor not functioning properly Repair or replace pump/motor
Motor controller malfunctioning See remedy column Refer to flash code troubleshooting chart