Toro 3000D Temperature Gauge GM, Thermistor GM, Handle the hot oil with extreme care to prevent

Temperature Gauge (GM 3000)

The temperature gauge can be tested using a new gauge as a substitute or by the use of a DC voltage source and a variable resistance box.

1.Connect the temperature gauge to the variable re­ sistance and DC voltage source (Fig. 34).

2.Adjust resistance until the gauge needle points to following test points on the gauge (Fig. NO TAG):

A.At 150_F the resistance setting should be from 113 to 123 ohms.

B.At 180_F the resistance setting should be from

68 to 73 ohms.

C.At 240_F the resistance setting should be from

24 to 37 ohms.

3.Disconnect the voltage source, gauge, and variable resistance.

	150_F		180_F	240_F
	G
S	I
VARIABLE		12 VDC
RESISTANCE
	BACK	–	+

Figure 55

Thermistor (GM 3000)

The thermistor is located on the bottom right side of the water pump, which is located on the rear end of the en­ gine block. It has a connector which a tan wire (Fig. 56).

1.Lower the coolant level in the engine and remove the thermistor from the water pump.

2.Put the thermistor in a container of oil with a ther­ mometer and slowly heat the oil (Fig. 57).

CAUTION
	Figure 56
Handle the hot oil with extreme care to prevent
personal injury or fire.

3.Check the resistance of the thermistor with a multi­ meter (ohms setting) as the temperature increases. The following resistance readings should be indicated:

108 to 78 OHMS at 140_F (60_C)

59 to 51 OHMS at 212_F (99_C)

Figure 57

Electrical System Page 6 – 30 Groundsmaster 3000/3000–D