32DFR114.A
4 - 3
TABLE 4-1: TROUBLESHOOTING GUIDE
Function
Symptom
Possible Cause
Remedy
Main circuit breaker
tripped
Reset main circuit breaker.
Hydraulic pump circuit
breaker tripped
Reset circuit breaker.
No input power to
ramp harness
connector J1, pin 6
(blue lead)
Check for input power at ramp harness
connector pin J1-6. Repair wiring, as required.
No signal from
STOW/DEPLOY
switch to ramp
harness connector J1,
pin 2 (red lead)
Check for STOW REQ signal at ramp interface
connector pin J1-2. Repair wiring, as required.
STOW/DEPLOY
switch defective
Replace or repair STOW/DEPLOY switch.
Main ramp power
switch defective.
Replace or repair main ramp power switch.
Pump solenoid
defective
Replace pump solenoid.
Pump relay defective
Replace pump relay.
Electronic controller
defective
Check for PUMP SOLENOID INPUT signal at
controller connector pin J4-4. Replace controller,
if necessary.
Hydraulic pump does
not operate; pump
solenoid does not
operate
Pump wiring harness
defective
Check pump-wiring harness. Repair wiring, as
required.
Needle valves closed
Adjust valves as shown in section C.5 in this
chapter.
Needle valves clogged
Clean needle valves. Adjust valves as shown in
section C.5 in this chapter.
Hydraulic pump wiring
harness defective
Check for STOW VALVE INPUT signal at
hydraulic pump assy harness connector J9
(white lead). Repair wiring, as required.
Electronic controller
defective
Check for STOW VALVE INPUT signal at
controller connector pin J4-2. Replace controller
if required.
Directional valve
defective
Replace hydraulic pump assy.
Hydraulic rotary
actuator defective
Replace hydraulic rotary actuator.
STOW
function
inoperative
or erratic
Pump solenoid
operates, but no ramp
movement occurs
Hydraulic pump
defective
Replace hydraulic pump.
