Specifications 6; High Temperature Warning Switch - Toro Groundsmaster 3505-D Service Manual

High Temperature Warning Switch

The high temperature warning switch is located on the
water pump housing on the rear of the engine block (Fig.
20). The high temperature warning switch has a gray
wire connected to it.
The Standard Control Module monitors the operation of
the high temperature warning switch. If the ignition
switch is in the ON position and the high temperature
warning switch has closed due to excessive coolant
temperature, the Module Over Temperature Warning in-
put LED should be illuminated. The high temperature in-
dicator light on the control panel should also illuminate.
If the cutting decks are engaged when the high tempera-
ture warning switch closes, the decks should shut off.
Testing
CAUTION
Make sure engine is cool before removing the
temperature switch.
1. Make sure ignition switch is in the OFF position. Low-
er coolant level in the engine and remove the tempera-
ture switch.
2. Put switch in a container of oil with a thermometer
and slowly heat the oil (Fig. 21).
CAUTION
Handle the hot oil with extreme care to prevent
personal injury or fire.
3. Check continuity of the switch with a multimeter
(ohms setting).
A. The high temperature warning switch is normally
open and should close between 216 to 226
o
108 C).
B. The meter should indicate more than 600 ohms at
o o
70 F (21 C).
C. The meter should indicate approximately 460
o o
ohms at 100 F (38 C).
D. The meter should indicate from 54 to 78 ohms at
o o
200 F (93 C).
Electrical System
4. Allow oil to cool while observing temperature. The
high temperature warning switch should open at about
o
208 F (98
5. Replace switch if specifications are not met.
6. Install 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 16 to 20 ft--lb (21.7 to 27.1 N--m).
C. Reconnect wire to switch.
7. Fill engine cooling system (see Traction Unit Opera-
tor's Manual).
1. Water pump housing
o
F (102 to
Page 5 - - 16
o
C).
1
2
Figure 20
2. Warning switch
Figure 21
Groundsmaster 3505--D