Service manual

Electrical Service Manual V4.0
4
4-5
CURTIS 1227 CONTROLLER
Machine will not move.
Suspected bad t
hrottle system
Raise machine
drive wheels and
support with
suita
ble stands.
Attach the (-) lead of a DC voltmeter to the B(-)
ter
minal. With the (+) lead measure the voltage at Pin
#2 o
n the 16 pin connector on the Curtis control.
Dep
ress and release the foot pedal slowly.
Turn the machine
power on.
Did the meter
display a sweeping
voltage fro
m about 0
volts to 5 volts?
The potentiometer
system is wor
king
properly
YES
Open the throttle pedal assembly. Attach
the (-) lead of a DC voltmeter to the B(-)
terminal. With the (+) lead measure the
voltage at the center terminal of the
speed p
otentiometer. Rotate the speed
kno
w slowly back and forth
Did the meter
display a sweepin
g
voltage fro
m about 0
volts to 5 volts?
Check the wiring and
connections between the speed
controller and th
e
pot
entiometer.
YES
NO
With a DC voltmeter measure
fro
m the the right outside
terminal to the lef
t outside
terminal on the potentiometer
Did the meter
display between 5.0
and 4.5 volts?
The potentiometer
is b
ad
YES
NO
With a DC voltmeter measure from Pin #1 to Pin #3 on
the 16 pin Molex connector on the Curtis control.
NO
Did the meter
display betw
een 5.0
and 4.5 volts?
The Curtis control has
failed
. Replace control.
NO
Repair the wiring between
the Cur
tis control and the
poten
tiometer.
YES