Temperature Sender - Toro Groundsmaster 4100-D Service Manual

Temperature Sender

The temperature sender is located near the alternator
on the water flange attached to the engine cylinder head
(Fig. 36). There is a gray wire attached to the terminal
of the switch.
Testing
1. Lower coolant level in the engine and remove the
temperature sender from water flange.
2. Put switch in a container of oil with a thermometer
and slowly heat the oil (Fig. 37).
CAUTION
Handle the hot oil with extreme care to prevent
personal injury or fire.
NOTE: Prior to taking resistance readings with a digital
multimeter, short the meter 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
from from the measured value of the component you are
testing.
3. Check resistance of the sender with a multimeter
(ohms setting) as the temperature increases.
A. The meter should indicate more than 600 ohms at
o o
70 F (21 C).
B. The meter should indicate approximately 460
o o
ohms at 100 F (38 C).
C. The meter should indicate from 54 to 78 ohms at
o o
200 F (93 C).
D. Replace sender if specifications are not met.
4. Install sender to the water flange.
A. Clean threads of water flange and sender thor-
oughly. Apply thread sealant to the threads of the
sender.
B. Screw sender into the water flange. Torque send-
er from 16 to 20 ft−lb (21.7 to 27.1 N−m).
C. Reconnect gray wire to sender. Apply skin−over
grease (Toro Part No. 505−165) to sender terminal.
5. Fill engine cooling system (see Operator's Manual).
Electrical System
1. Temperature sender
Rev. E
Page 5 − 24
2
Figure 36
2. Alternator
VOA
Figure 37
Groundsmaster 4100−D
1