Toro Groundsmaster 3280-D Service Manual page 281

Testing the High Temperature Warning Switch (continued)
Groundsmaster ® 3280-D/3320
05138SL Rev B
If the radiator or engine is hot, pressurized hot coolant can escape
and cause burns.
Do not open the radiator cap or drain the radiator when the coolant
is hot. Ensure that the engine is cool before removing the high
temperature warning switch from the engine.
3. Lower the coolant level in the engine.
4. Remove the wire harness connector from the high temperature warning
switch, and remove the switch from the engine.
g226814
5. Put the end of the switch in a container of oil with a thermometer and then
slowly heat the oil
The oil is hot and could cause personal injury or fire.
Handle the hot oil with extreme care.
Note: Before taking the small resistance readings with a digital multimeter,
short the multimeter test leads together. The meter will display a small
resistance value (usually 0.5 ohms or less). This resistance is because of the
internal resistance of the multimeter and test leads. Subtract this value from
the measured value of the component you are testing.
6. Check the resistance of the switch with a multimeter (ohms setting) as the oil
temperature increases.
A. The meter should indicate more than 600 ohms at 21°C (70°F).
B. The meter should indicate approximately 460 ohms at 38°C (100°F).
C. The meter should indicate from 54 to 78 ohms at 93°C (200°F).
7. If the switch does not meet the specifications, replace the switch.
DANGER
Figure 153
(Figure 153).
CAUTION
Page 6–53 Electrical System: Testing the Electrical Components