FORM NO. 56043057 ConvertaMAX
™
28/34, I-MAX
™
28HD/34HD, BA 750/850 -
35
WHEEL DRIVE SYSTEM
TROUBLESHOOTING GUIDE ELECTRICAL
Possible Symptom
1
No forward and no reverse wheel drive
SYMPTOM ONE
Note: Do all testing with control panel R2 speed limiting pot in the maximum position, the drive wheel jacked up off the floor, key switch ON, and
the drive paddle activated (pushed Fwd or pulled into Rev.)
Part A: Wheel drive system motor load circuit troubleshooting guide
Note A: The drive wheel motor harness disconnect is located in the lower rear of the machine frame between the caster wheels.
No Forward and no
Reverse wheel drive
(see Figure 1).
1. Replace the F3
(40 Amp) wheel drive
circuit breaker.
2. Still error 3 code
No
Still error 3 code, see in
the Electrical System
the speed control fault
code chart for additional
troubleshooting info.
1. Repair or replace
the battery input wiring
to the A1 speed con-
troller.
2. Still error 3 code.
Separate the motor wiring
harness (see note A) &
check for controller output
voltage by activating the
drive paddle. 24V controller
should have 24V Fwd &
15V in Rev. 36V controller
should have 36V Fwd &
22V Rev.
Repair or replace
the M6 wheel drive
motor
See part B wheel drive
control circuit trouble-
shooting guide.
No
Yes
Yes
Check control panel
display for error 3 call-
out
1. Check wheel drive sys-
tem for mechanical over-
load & remove cause.
2. Try resetting the F3 40A
drive motor circuit breaker.
3. Still no drive, check the
F3 breaker’s continuity.
Check for 24V or 36V at
the A1 speed controller’s
battery Pos(+) & Neg(-)
terminals
Yes
Yes
Yes
Yes
Yes
No
No
revised 12/02