Unit Will Not Lift Up From Ground Control Toggle Switch; Platform Will Not Lift Up From Ground Control Toggle Switch - JLG 10VP Service And Maintenance Manual

SECTION 3 - TROUBLESHOOTING

Platform Will Not Lift Up From Ground Control Toggle Switch

Overview Of Procedure
The following procedure examines the complete ground control circuit from the battery all the way to the pump motor for
wiring or components which could be causing a failure of that circuit.
Check For These Obvious Conditions First:
• Battery voltage 24 volts. (Fully charge batteries)
• Battery connections clean and tight.
• Key switch positioned to Ground (GRND) control.
• Emergency stop switch pulled out. (Reset Position)
• Ground control power supply and wiring, OK (Table 3-4).
• Manual descent valve closed.
• 5 amp fuses on power and pump circuits, OK.
• Hydraulic oil level, OK.
• Weight in platform does not exceed machine maximum capacity.
Table 3-24. Unit Will Not Lift Up From Ground Control Toggle Switch.
STEP
Does the pump motor run when lift up is selected at the ground con-
1.
trol switch?
Note: Steps 2 thru 9 are to be performed with LIFT UP selected at the
ground control.
2. Check terminal 30 and 85 on the ground control relay for ground. Is
ground contact OK?
Check continuity across terminals 87 and 30 on the ground control
3.
relay. Is there continuity? (Relay must be energized)
4. Check the Black wire from terminal 87 on the ground control relay to
the lift up/down ground control switch. Is there continuity with B –?
5. Check for continuity across the terminals (Black to Tan 3-1 and Tan
55-1) of the lift up/down ground control toggle switch. Is there con-
tinuity?
6. Check the Tan, 3-1 wire for continuity from the lift up/down ground
switch to the lift up coil. Is there continuity?
Check the Tan, 55-1 wire from the lift up/down ground switch to the
7.
pump contactor for continuity. Is there continuity?
Check the Yel/Red, 2-6 wire from the pump motor to the pump con-
8.
tactor and lift-up coil for voltage. Is there voltage?
9. Check the wire from the lift switch (Tan 55-1) pump contactor to the
battery (-) terminal for continuity. Is there continuity?
Check the pump motor pressure relief setting. Is it within specifica-
10.
tion per Service Manual?
3-34
ACTION
– JLG Lift –
SPEC YES
Go to Steps 5,6
—
and 10
Ground Go to Step 3
— Go to Step 4
— Go to Step 5
— Go to Step 6
— Go to Step 7
— Go to Step 8
24 Volts Go to Step 9
— —
—
NO
Check Ground
Power Circuit
(Table 3-4)
Before Continu-
ing to Step 3
Repair Wiring or
Connection
Replace Relay
Repair Wiring or
Connection
Replace Lift Up/
Down Ground
Control Switch
Repair Wiring or
Connection
Repair Wiring or
Connection
Repair Wiring or
Connection
Repair Wiring or
Connection
Set as Required
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