Toro 41188, Service Manual

Page: 108 / 353

Multi Pro 1750
Page 5 − 6
Electrical System
Flow Meter Sensor Test Harness
Special Tools Needed
Flow meter sensor test harness (fabricated using the
information provided here)
Multimeter with frequency measurement capability
(12V square wave)
Instructions
1. Park machine on a level surface, stop engine and en-
gage parking brake. Remove key from ignition switch.
2. Disconnect flow meter sensor from wire harness and
check wire harness for circuit problems before testing
speed sensor (see Flow Meter Sensor in the Compo-
nent Testing section of this chapter).
3. With sensor installed in flow meter, connect flow me-
ter sensor test harness between sensor and machine
wire harness.
4. Plug red wire (from connector pins 3) into the positive
voltage port on the multimeter and black wire (from con-
nector pins 1) into ground port on the multimeter.
5. Set multimeter to measure frequency (12V square
wave).
6. Watch the meter as an assistant begin spraying (ve-
hicle remains stationary). A frequency reading should
appear and remain relatively constant. Making adjust-
ments to the spray system pressure or changing noz-
zles should increase or decrease the frequency reading
accordingly.
7. If frequency is not registered or is erratic, verify orien-
tation of grooves on sensor body. The grooves must be
aligned parallel to the flow meter body (see Flow Meter
Sensor in the Service and Repairs section of this chap-
ter). If the sensor grooves are not aligned:
A. Loosen sensor lock nut.
B. Rotate sensor clockwise (sensor turns into the
port) until grooves are aligned.
C. Tighten the lock nut from 15−20 in−lbs (1.7 to 2.3
N−m) and re−test.
8. If frequency continues to not register or is erratic, re-
move and re−install sensor.
A. Thread jam nut against sensor hex head.
B. Thread sensor into flow meter body until bottom
of sensor jam nut is 0.38 in. (9.6 mm) form flow meter
body.
Figure 7
Flow Meter Sensor Test Harness
TO SPEED SENSOR
CONXALL 3180−3SG−318
FEMALE CONNECTOR
NEGATIVE (−)
CONNEECTORS COMPATIBLE WITH
MULTIMETER USED
POSITIVE (+)
4 ft (1.2 m)
TO MACHINE HARNESS
CONXALL 5180−3PG−318
MALE CONNECTOR
1
2
3 1
2
3
C. Turn sensor out (counterclockwise) until orienta-
tion groove on top of sensor is parallel with flow me-
ter body.
D. Hold sensor in position and turn jam nut down to
contact flow meter body. Tighten jam nut from 15 to
20 in−lb (1.7 to 2.3 N−m).
9. If frequency measurement does not register, is errat-
ic, or does not change with changes to spray system
pressure or nozzle size after verifying alignment of sen-
sor and re−installation, remove and replace the flow me-
ter sensor. See Flow Meter Sensor in the Service and
Repairs section of this chapter.