Dual Temperature Switch - Toro Groundsmaster
4000?D Service Manual

PRELIMINARY – For Toro Distributor and Toro Company use only.

Dual Temperature Switch

The dual temperature switch is attached to the engine
near the alternator on the water flange attached to the
engine cylinder head (Fig. 32). Two (2) electrical har-
ness wires (a blue wire and a yellow wire) are attached
to the switch.
The terminal on the switch is used to activate the engine
over temperature warning. The warning illuminates the
overtemp warning light and also causes the PTO to dis-
engage. The harness blue wire attaches to this switch
terminal.
The wire lead on the switch is used to shutdown the en-
gine. The harness yellow wire attaches to this switch
lead.
Testing
Make sure engine is cool before removing the
temperature switch.
1. Lower coolant level in the engine and remove the
dual temperature switch from the engine water flange.
2. Put switch in a container of oil with a thermometer
and slowly heat the oil (Fig. 33).
Handle the hot oil with extreme care to prevent
personal injury or fire.
3. Check continuity of the switch with a multimeter
(ohms setting). Both circuits of the temperature switch
are normally open and should close at the following tem-
peratures:
A. The warning terminal should open from 214
o
226 F (101 to 108
B. The shutdown wire lead should open from 234
o
246 F (112 to 119
4. Replace switch if necessary.
5. Install switch to the water flange.
A. Clean threads of cylinder head and switch thor-
oughly. Apply thread sealant to the threads of the
switch.
Electrical System
CAUTION
CAUTION
o
C).
o
C).
B. Screw switch into the cylinder head and tighten.
C. Connect harness wires to switch.
6. Fill engine cooling system.
1. Dual temp switch
1
o
to
o
to
1. Dual temperature switch
2. Warning (terminal)
Page 5 − 24
1
2
Figure 32
2. Alternator
VOA
Figure 33
2
3
Figure 34
3. Shutdown (wire lead)
Groundsmaster 4000−D