User manual

Rev. D
Multi Pro 5700--D
Page 5 -- 19
Electrical System
Pulse Width Modulated (PWM) Valve Solenoid
The Pulse Width Modulated (PWM) Valve which con-
trols hydraulic flow to the spray pump motor includes an
electric solenoid (Fig. 30). When the spray console rate
switch is depressed, the available current to the PWM
valve s olenoid is changed. This solenoid current change
causes a valve shift and subsequent change in hydrau-
lic flow to the spray pump motor. Testing of the PWM
Valve solenoid can be done without removing the sole-
noid.
Testing
NOTE: Prior to taking small resistance readings with a
digital multimeter, short the meter test leads together.
The meter will display a small resistance value (usually
0.5 ohms or less). This resistance is due to the internal
resistance of the meter and test leads. Subtract this val-
ue from from the measured value of the solenoid y ou are
testing.
1. Make sure ignition switch is off. Disconnect PWM
Valve solenoid electrical connector.
2. Measure resistance between the two solenoid con-
nector terminals. The resistance for the solenoid coil
should be approximately 9.6 ohms.
NOTE: The solenoid coil on machines with serial num-
bers below 260000300 is not available as a separate
component (shown in Fig. 30). On machines with serial
numbers above 260000300, the coil is available as a
separate component (Fig. 31). Refer to your parts cata-
log for replacement part information.
3. Reconnect electrical connector to the solenoid.
1. PWM valve
2. Solenoid
3. Solenoid connector
Figure 30
3
2
1
1. PWM valve
2. Solenoid coil
3. O--ring
4. Nut
Figure 31
3
2
4
1
SERIAL NUMBER ABOVE 260000300
Electrical
System