JLG 15ELI Service Manual - Manual (Page 36)

SECTION 3 - TROUBLESHOOTING
3-2 – JLG Lift – 3120779
Table 3-1. AC Unit - Troubleshooting
TROUBLE PROBABLE CAUSE REMEDY
Platform does not rise.
Power source is OFF or unplugged). Check power source or Ground Sta-
tion Key Switch.
Red emergency stop button is
engaged (PUSHED IN) on either
ground control station or on platform. Disengage (TURN CLOCKWISE) red
emergency button until it pops out.
Foot Brake is not engaged. Engage Foot Brake at front of
machine.
Control relay not functioning. Replace control relay.
Motor start relay not functioning. Replace motor start relay.
Fuse(s) blown. Replace blown fuse. If fuse blows
again check electrical circuit for short
circuit.
Unit wiring not properly grounded. Check all grounds in the wiring.
Check for loose wire(s) on Floor Brake
Limit Switch (causing an open circuit). Properly reinstall wire to limit switch.
Platform lowers by itself.
Manual descent valve open. Close manual descent valve.
Hydraulic hose and/or fittings loose
causing a hydraulic pressure leak. Tighten hydraulic hose and/or fittings.
Lift DOWN solenoid valve not function-
ing. Replace Lift DOWN solenoid valve.
Unit leaking hydraulic oil.
Hydraulic hose and/or fittings loose. Tighten hydraulic hose and/or fittings.
Valve and/or plug loose. Tighten valve and/or plug.
Breather cap on tank is saturated or
clogged with oil. Replace breather cap on tank.
Hydraulic oil tank over-filled. Lower oil level to full mark on dipstick.
Unit lowers very slowly.
Flow control valve not functioning. Replace flow control valve.