Dual Temperature Switch (Machines With Operator Cab) - Toro Groundsmaster 360 Service Manual

Dual Temperature Switch (Machines with Operator Cab)

On Groundsmaster 360 machines equipped with an op-
erator cab, the dual temperature switch includes two (2)
normally open circuits used to monitor engine coolant
temperature. These switch circuits are the high temper-
ature warning circuit and the high temperature shut-
down circuit. The dual temperature switch is attached to
the engine water pump housing (Fig. 68).
If engine coolant temperature rises to approximately
o o
220 F (105 C), the high temperature warning circuit
closes. This closed circuit causes the High Temperature
Warning Light on the console to illuminate and also
causes the PTO (cutting deck) to shut down.
If engine coolant temperature rises to approximately
o o
240 F (115 C), the high temperature shutdown circuit
closes and causes the engine to shut down.
The Toro Electronic Controller (TEC) monitors the op-
eration of the dual temperature switch. Before perform-
ing the following testing procedure, the switch and its
circuit wiring should be tested as an electrical input us-
ing the Diagnostic Display (see Diagnostic Display in the
Troubleshooting section of this chapter).
Testing
1. Park machine on a level surface, lower cutting deck,
stop engine, apply parking brake and remove key from
ignition switch. Raise and support hood.
CAUTION
Make sure engine is cool before removing the
dual temperature switch from engine. Do not
open radiator cap or drain coolant if the radiator
or engine is hot. Pressurized, hot coolant can es-
cape and cause burns.
2. Lower the coolant level in the engine and remove the
dual temperature switch from the engine.
3. Put the end of the switch in a container of oil with a
thermometer and slowly heat the oil (Fig. 69).
CAUTION
Handle the hot oil with extreme care to prevent
personal injury or fire.
Electrical System
4. Check resistance of the switch with a multimeter
(ohms setting) as the oil temperature increases.
A. The high temperature warning circuit is normally
open (high resistance) and should close (continuity)
o
from 214 to 226
B. The high temperature shutdown circuit is normal-
ly open and should close from 234
o
119 C).
5. Replace the switch if either of the specifications is not
met.
6. After testing is complete, install temperature switch
to the engine housing.
A. Clean threads of housing and switch thoroughly.
Apply thread sealant to the threads of the switch.
B. Thread switch into the housing. Torque switch
from 22 to 28 ft- -lb (30 to 38 N- -m).
C. Reconnect harness wires to temperature switch.
7. Fill engine cooling system. Lower and secure hood.
1. Dual temp switch
2. Warning circuit
Page 5 - - 50
o o o
F (101 to 108 C).
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to 246
2
1
3
Figure 68
3. Shutdown circuit
Figure 69
Groundsmaster 360
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F (112 to
1