Toro 4100-D Dual Temperature Switch, Groundsmaster 4100--D 5 -- 29 Rev. a Electrical System

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. 43). 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 wire harness blue wire attaches to the switch terminal.

The wire lead on the switch is used to shutdown the en- gine. The wire harness yellow wire attaches to the switch lead.

Testing

CAUTION

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. 45).

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). Both circuits of the temperature switch are normally open and should close at the following tem- peratures:

A.The warning terminal should close from 214o to

226o F (101 to 108o C).

B.The shutdown wire lead should close from 234o to 246o F (112 to 119o C).

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.

B.Screw switch into the cylinder head and torque switch from 22 to 28 ft--lb (29.4 to 39.2 N--m).

C.Connect harness wires to switch.

6.Fill engine cooling system.

1

2

Figure 43

1. Dual temp switch 2. Alternator

1	3	Electrical System
	2
	Figure 44

1.	Dual temperature switch	3. Wire lead (shutdown)
2.	Terminal (warning)

Figure 45

Groundsmaster 4100--D Page 5 -- 29 Rev. A Electrical System