Service Manual

Groundsmaster 3500Page 6 − 24Electrical System
High Temperature Warning and Shutdown Switches (Diesel Engines Only)
The high temperature warning and shutdown switches
are located on the water pump housing, which is located
on the rear end of the engine block (alternator end) (Fig.
31).
CAUTION
Make sure engine is cool before removing the
temperature switch.
1. Lower coolant level in the engine and remove the
temperature switch.
2. Put switch in a container of oil with a thermometer
and slowly heat the oil (Fig. 32).
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 226F (102 to
108C).
B. The high temperature shutdown switch is normal-
ly open and should close between 225 to 235F (107
to 113C).
4. Allow oil to cool while observing temperature.
A. The high temperature warning switch should
open at about 208F (98C).
B. The high temperature shutdown switch should
open at about 219F (104C).
5. Replace switch if necessary.
1. Temp. warning switch
2. Temp. shutdown switch
3. Water pump housing
Figure 31
2
1
3
Figure 32
VOA