Check TM for testing procedure.....bottom of post:
2-92 COOLANT TEMPERATURE SENDER.
NOTE
Engine must be cool when performing this test
2-92.1 Testing.
a Shut down generator set
b. Open left side engine access door
c. Disconnect and tag electrical lead from coolant temperature sender (4, FIGURE 2-25)
d. Set multimeter for ohms and connect to coolant temperature sender terminal and casing. Multimeter indication
should be greater than 300 ohms.
e. Start generator set and observe multimeter.
f As engine operates and coolant temperature rises, multimeter indication should decrease,
g. Shut down generator set.
h Replace coolant temperature sender if indications are other than above
i. Connect electrical lead, remove tag, and dose left side engine access door.
2-92.2 Removal.
a Shut down generator set
b Open left side engine access door and disconnect negative battery cable
c Tag and disconnect temperature sender (4, FIGURE 2-25) lead.
d Unscrew temperature sender (4) from thermostat housing.
ARMY TM 9-6115-642-24