Service Manual

Groundsmaster 4100--D/4110--D Page 5 -- 39 Electrical System
Temperature Sender
The temperature sender is located near the alternator
onthe water flange attached to the engine cylinderhead
(Fig. 50). The resistance of the temperature sender re-
duces as the engine coolant temperature increases.
There is a gray harness wire attached to the switch.
Testing
1. Lower coolant level in the engine, disconnect gray
harness wire from temperature sender and remove the
temperature sender from water flange.
2. Suspendsender in a container of oil with a thermom-
eter and slowly heat the oil (Fig. 51).
CAUTION
Handle the hot oil with extreme care to prevent
personal injury or fire.
NOTE: Prior to taking resistance readings with a digital
multi meter, shortthemeter test leads together. The me-
ter will display a small resistance value (usually 0.5
ohms or less). This resistance is due to the internal re-
sistance of the meter and test leads. Subtract this value
fromfrom themeasured value ofthe componentyou are
testing.
3. Check resistance of the sender with a multimeter
(ohms setting) as the temperature increases. Replace
sender if specifications are not met.
COOLANT TEMP
TEMP SENDER RESISTANCE
100
o
F(38
o
C) 460 ohms (approximate)
160
o
F(71
o
C) 140 ohms (approximate)
200
o
F(93
o
C) 54 to 78 ohms
221
o
F (105
o
C) 50 ohms (approximate)
4. After testing is complete, install sender to the water
flange.
A. Thoroughly clean threads of water flange and
sender. Apply thread sealant to the threads of the
sender.
B. Screw sender into thewater flange.Torquesend-
er from 16 to 20 ft--lb (22 to 27 N--m).
C. Reconnect gray harness wire to sender. Apply
skin--over grease (Toro Part No. 505--165) to sender
terminal.
5. Fill engine cooling system.
Figure 50
1. Temperature sender 2. Alternator
1
2
Figure 51
Electrical
System