JLG 20VP (3120728) Service Manual - Manual (Page 84)

SECTION 3 - TROUBLESHOOTING
3-24 – JLG Lift – 3120728
Won’t Climb Grade
Overview Of Procedure
The following procedure checks the drive motor and attached components for component failure, misadjustment due to
wear.
Check For These Obvious Conditions First:
• Batteries are Fully Charged (24 Volts)
• Speed Control is Set to Maximum
• Is Grade within the Maximum Allowable Specification of 15% Grade (8.5 degrees)
• Does the Travel Surface allow for Proper Drive Wheel Traction
• Is Platform Load within the Maximum Rated Capacity
Table 3-14. Won’t Climb Grade
STEP ACTION SPEC YES NO
1. Does machine drive straight on a level surface?
— Go to Step 2
Refer to Machine
Won’t Drive
Straight
(Table 3-18)
2. Are both the left and right drive motor, slip-clutches, located
between the drive motor and the drive wheels, working properly?
— Go to Step 3
Repair, Replace
or Adjust Slip
Clutch
3. Do the left and right drive motor brakes release properly and allow
the drive wheels to rotate freely ?
— Go to Step 4
Dragging?
Repair, Replace
or Adjust Brakes
4. Check the amperage output of the on the drive motor leads. They
should not exceed 70 amps while pulling a grade.
—
Controller will
Shut Drive Down
and will flash a 7
LED Code
Go to Step 5
5. Check the condition of the drive motor brushes.
— OK, go to Step 6
Worn down,
replace brushes
or drive motor
6. If all above is OK, Drive motors are working properly. Consult Fac-
tory.
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