JLG 400CRT ANSI Service Manual - Manual (Page 50)

SECTION 3 - TROUBLESHOOTING
3-8 – JLG Lift – 3121111
Table 3-4. Electrical System Troubleshooting
TROUBLE PROBABLE CAUSE REMEDY
HAND CONTROLLER
Regardless of which way handle is moved, only
one function occurs
Improper or loose wiring to the solenoid(s) Check all wiring for proper connections
Directional valve stuck in one direction Repair or replace valve
Valve will not function when handle is moved in
either direction
Joystick not activated within the 3 seconds after
function switch was depressed Reactivate function switch
No electrical power to handle Check electrical input to hand controller (12V)
No electrical power to valve Check electrical output of printed circuit board and
electrical signal at the valve
Improper ground Check for proper grounding of handle
Defective controller Repair or replace controller
Microswitches on controller bad or need adjust-
ment Adjust or replace switches
CONTROL SWITCHES
No response to a function control switch
Emergency stop switch not positioned properly Place emergency stop switch to on
Platform/Ground select switch not positioned
properly Place switch to platform or ground, as necessary
Circuit breaker open Determine and correct cause. Reset circuit
breaker
No voltage present at emergency stop switch Check battery cable from battery to emergency
stop switch for proper connection or damage.
Repair or replace cable as necessary
Emergency stop switch not functioning properly Replace switch
No voltage supplied to start relay from emergency
stop switch Check battery cable from switch to relay for proper
connection or damage. Repair or replace cable as
necessary
No voltage input at terminal strip Check wire from battery to terminal strip for proper
connection or damage. Repair or replace cable as
necessary
No voltage present at circuit breaker Check wire from terminal strip to battery for proper
connection or damage. Repair or replace cable as
necessary
Defective circuit breaker Replace circuit breaker
No voltage present at Platform/Ground select
switch Unplug ground control box harness from platform
receptacle. check wire from applicable pin in plug
to control box power switch for proper connection.
Using suitable test meter, perform continuity test
on wire. Repair or replace harness as necessary
Defective Platform/Ground select switch Replace Platform/Ground select switch