Service manual
Electrical Service Manual V4.0
5
5-6
CURTIS 1228 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
#4 o
n the 18 pin connector on the Curtis control.
Rotate the spee
d know slowly back and forth.
Turn the machine
power o
n and
THEN tap
e down
handle bar
button(s).
Did the meter
display a sweeping
voltage fro
m about 0
volts to 5 volts?
Remove the tape
from the handle
bar buttons and re-
mea
sure for
vo
ltage
Did the meter
stay at zero?
The potentiometer
system is working
properly
Disconnect the
rev
erse switch and
retest for voltage
Pin #4 on the 18
pin connector.
Did the meter
stay at zero?
The reverse switch is
bad. Replace the switch
A handle bar button is bad.
Check each one for continu
ity
and replace the one w
ith
constant continuity
YES
NO
YES
NO
YES
Attach the (-) lead of a DC
voltmeter to the B(-) termina
l.
With the (
+) lead measure the
voltage a
t the center terminal of
the speed potentiometer.
Rotate the spee
d know slowly
back and forth
Did the meter
display a sweepin
g
voltage fro
m about 0
volts to 5 volts?
Check the wiring to and from
the handle bar button a
nd the
buttons themsel
ves.
YES
NO
With a DC voltmeter measure
fro
m the the right outside
terminal to the lef
t outside
termina
l on the potentiometer
Did the meter
display betw
een 5.0
and 4.5 volts?
The potentiometer
is b
ad
YES
NO
With a DC voltmeter measure from Pin #3 to Pin #13
on the 18 pin Molex connector on the C
urtis 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