Toro Groundsmaster 5900 Series Service Manual page 363

Testing (continued)
Groundsmaster ® 5900 & 5910
16227SL Rev B
4. Disconnect the machine wire harness connector from the relay. Remove
relay from mounting bracket for 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 value from the measured value for
the tested component.
g288554
5. Using a multimeter (ohms setting), measure coil resistance between terminals
85 and 86 (Figure 243). Resistance should be between 70 and 100 ohms.
6. Verify infinite resistance (no continuity) between terminals 30 and 87.
7. Connect multimeter (ohms setting) leads to relay terminals 30 and 87.
Ground terminal 86 and apply +12 VDC to terminal 85. The relay should
make and break continuity between terminals 30 and 87 as +12 VDC is
applied and removed from terminal 85.
8. Disconnect meter leads and jumper wires from the relay terminals.
Reconnect machine wire harness connector to relay.
9. Install and secure panels and covers removed to access relays.
10. Turn the battery−disconnect switch to the ON position before returning the
machine to service.
86
85
Figure 243
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85 86
87
87
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Electrical System: Component Testing