Temperature Sender - Toro Groundsmaster
4000?D Service Manual

PRELIMINARY – For Toro Distributor and Toro Company use only.

Temperature Sender

The temperature sender is located near the alternator
on the water flange attached to the engine cylinder head
(Fig. 30). There is a gray wire attached to the terminal
of the switch.
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. 31).
Handle the hot oil with extreme care to prevent
personal injury or fire.
NOTE: Prior to taking resistance readings with a digital
multi meter, 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 from 54 to 78 ohms at
o o
200 F (93.3 C).
B. Replace sender if specification is 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 and tighten.
C. Reconnect gray wire to sender. Apply skin−over
grease (Toro Part No. 505−165) to sender terminal.
5. Fill engine cooling system.
Groundsmaster 4000−D
CAUTION
1. Temperature sender
Page 5 − 23
1
2
Figure 30
2. Alternator
VOA
Figure 31
Electrical System