High Temperature Warning Switch (Machines Without Operator Cab) - Toro Groundsmaster 360 Service Manual

High Temperature Warning Switch (Machines without Operator Cab)

The high temperature warning switch is attached to the
water pump housing on the engine (Fig. 64). This switch
is normally open and closes when engine coolant tem-
perature reaches approximately 220
engine coolant temperature causes the warning switch
to close, the high temperature warning light on the con-
sole will illuminate and also the cutting deck will shut
down. There is a yellow harness wire attached to the
warning switch on 2WD machines. On 4WD machines,
a violet harness wire attaches to the warning switch.
On 2WD machines, the Standard Control Module
(SCM) monitors the operation of the high temperature
warning switch. If the high temperature warning switch
closes (high engine coolant temperature), the SCM high
temperature warning LED should be illuminated.
On 4WD machines, the Toro Electronic Controller (TEC)
monitors the operation of the high temperature warning
switch.
Before performing the following testing procedure, the
temperature warning switch and its circuit wiring should
be tested as an electrical input using the SCM on 2WD
machines or the Diagnostic Display on 4WD machines
(see Standard Control Module or 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
temperature warning 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, remove wire
harness connector from high temperature warning
switch and remove the 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. 65).
CAUTION
Handle the hot oil with extreme care to prevent
personal injury or fire.
Electrical System
o o
F (105 C). If high
Page 5 - - 48
4. Check resistance of the warning switch with a multi-
meter (ohms setting) as the oil temperature increases.
The high temperature warning switch is normally open
(high resistance) and should close (continuity) from
o o o
216 to 226 F (102 to 108
5. Replace warning switch if specifications are not met.
6. After testing, install high temperature warning switch
to the engine housing.
A. Clean threads of housing and switch thoroughly.
Apply thread sealant to the threads of the switch.
B. Thread warning switch into the housing. Torque
switch from 16 to 20 ft- -lb (22 to 27 N- -m).
C. Connect wire harness connector to high temper-
ature warning switch.
7. Fill engine cooling system. Lower and secure hood.
Figure 64
1. High temperature warning switch
Figure 65
o
C).
1
Groundsmaster 360