Won't Climb Grade; Machine Drives In Opposite Direction - JLG 15MVL Series Service Maintenance Manual

6.16 DRIVE SYSTEM TROUBLESHOOTING

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 20% Grade
• Does the Travel Surface allow for Proper Drive Wheel Traction
• Is Platform Load within the Maximum Rated Capacity
STEP
1. Does machine drive straight on a level surface?
2. Do the left and right drive motor brakes release properly and allow the drive
wheels to rotate freely?
3. Check the amperage output of the on the drive motor leads. They should not
exceed 100 amps while pulling a grade.
4. Check the condition of the drive motor brushes.
5. If all above is OK, Drive motors are working properly. Consult Factory.

Machine Drives in Opposite Direction

STEP
1. At the Traction Control Module, check if the left drive motor power lead is
plugged into the M1 socket.
2. Remove the Right Drive Motor power lead at the Traction Control Module
(M2) and check if the WHITE wire is connected to the positive (+) terminal
and the BLACK wire is connected to the negative (–) terminal. (Reference
Figure 6-7., Electrical Diagram. (MVL/MSP)
3. Remove the Left Drive Motor power lead at the Traction Control Module
(M1) and check if the BLACK wire is connected to the positive (+) terminal
and the WHITE wire is connected to the negative (–) terminal. The Left
Motor Power lead is reversed from the Right Motor lead due to the reverser
harness. (Reference Figure 6-7., Electrical Diagram. (MVL/MSP)
3121231
Table 6-52. Won't Climb Grade
ACTION
Table 6-53. Machine Drive in Opposite Direction
ACTION
– JLG Lift –
SECTION 6 - TROUBLESHOOTING
SPEC YES
— Go to Step 2
— Go to Step 3
— Controller will Shut
Drive Down and will
flash a 7 LED Code
— OK, go to Step 6
— —
SPEC YES
— Go to Step 2
— Go to Step 3
— Consult
Factory
NO
Refer to Machine
Won't Drive Straight
(Table 6-54)
Dragging?
Repair, Replace or
Adjust Brakes
Go to Step 5
Worn down,
replace brushes or
drive motor
—
NO
Switch the Left and
Right Drive Motor
Power Leads at the
Traction Module
Rewire as
Necessary
Rewire as
Necessary
6-45