Hydraulic Solenoid Valve Coils - Toro Groundmaster Series Service Manual

Hydraulic Solenoid Valve Coils

Testing the Hydraulic Solenoid Valve Coils
Groundsmaster ® 3200, 3300 and 3310
19240SL Rev A
g304231
1. Main hydraulic manifold
2. Valve SV1 coil (raise)
3. Valve SV2 coil (lower)
4. Coil nut
Electric coil actuated hydraulic valves are used on the main manifold and the
optional Auxiliary Hydraulic Valve manifold. When the coil or the coil relay is
energized by the TDM, the hydraulic valve shifts to control hydraulic flow.
To assist in troubleshooting, identical replaceable solenoid coils can be
exchanged. If the problem follows the coil, the coil is likely at fault. If the problem
remains unchanged, something other than the coil is the likely problem source
(e.g. switch, circuit wiring, hydraulic problem).
Typically, a failed solenoid coil will either be shorted (very low or no resistance)
or open (infinite resistance).
1. Locate the hydraulic solenoid valve coil to be tested and disconnect the wire
harness connector from the coil. Check the harness connectors for damage
or corrosion and clean or repair if necessary.
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 value from the measured value of the
component you are testing to obtain an accurate reading.
2. Using a multimeter (ohms setting), measure the resistance between the two
(2) connector terminals on the solenoid coil. The resistance for the solenoid
coils is identified below:
A. The coils of solenoid valves SV1 and SV2 on the main hydraulic manifold
are the same. Resistance of these coils should be approximately 8.8
ohms when tested at 20° C (68° F).
Figure 106
5. Auxiliary hydraulic valve manifold (optional)
6. Auxiliary valve coil S1
7. Auxiliary valve coil S2
8. Coil spacer
Page 6–59 Electrical System: Testing the Electrical Components