Temperature Relay - Toro Groundsmaster 300 Series Service Manual

Temperature Relay (Fig. 18)
The temperature relay (Fig. 18, Item 18) works with the
temperature gauge to disconnect battery voltage to the
ignition system (gas engine) or fuel shut stop control unit
(diesel engine) if the engine temperature gets too hot.
The B & C terminals of the temperature relay have a
normally closed connection between them. If there is no
continuity between terminals B & C check the SFE-14
fuse inside the relay box.
A coil resistance may be read on the ohmmeter between
terminals B & S. No resistance, indicates an open coil.
If the coil is open, replace the temperature relay device.
Temperature Gauge Sending Unit (Fig. 19)
The temperature gauge sending unit is located on the
top of the cylinder head, near the thermostat .
1. Lower the coolant level in the engine and remove the
temperature gauge sending unit located near engine
thermostat.
2. Put the sending unit in a container of oil with a
thermometer and heat the oil.
3. With an Ohm meter connected as shown, the resis-
tance readings should changed as the temperature
increases (resistance should get lower as temperature
gets higher).
CAUTION
Handle hot oil with special care to prevent
personal injury or fire.
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Groundsmaster 300 Series Page 6 - 27
Figure 18
Figure 19
Testing