Checking The Radiator Fan Motor (For Jpn); Checking The Coolant Temperature Sensor - Yamaha YZ450FX 2019 Owner's Service Manual

• Positive tester probe 
Black "1"
• Negative tester probe 
Black "2"
b. Measure the resistance of the resistor.
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EAM30302
CHECKING THE RADIATOR FAN MOTOR
(For JPN)
1. Check:
• Radiator fan motor
Faulty/rough movement  Replace.
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a. Disconnect the radiator fan motor coupler
from the wire harness.
b. Connect the battery (DC 12 V) as shown.
• Positive battery terminal 
Blue "1"
• Negative battery terminal 
Black "2"
1
L
c. Measure the radiator fan motor movement.
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EAM30303
CHECKING THE COOLANT TEMPERATURE
SENSOR
1. Remove:
• Coolant temperature sensor
EWA14130
WARNING
• Handle the coolant temperature sensor
1
2
2
B
12V
8-66
ELECTRICAL COMPONENTS
with special care.
• Never subject the coolant temperature sen-
sor to strong shocks. If the coolant temper-
ature sensor is dropped, replace it.
2. Check:
• Coolant temperature sensor resistance
Out of specification  Replace.
Coolant temperature sensor re-
sistance
2512–2777 
Coolant temperature sensor re-
sistance
210–220 
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a. Connect the digital circuit tester () to the
coolant temperature sensor.
Digital circuit tester (CD732)
90890-03243
Model 88 Multimeter with tachom-
eter
YU-A1927
• Positive tester probe 
Green/White "1"
• Negative tester probe 
Black/Blue "2"
G/W
G/W
1
b. Immerse the coolant temperature sensor in a
container filled with coolant.
TIP
Make sure the coolant temperature sensor ter-
minals do not get wet.
c. Place a thermometer in the coolant.
d. Slowly heat the coolant, and then let it cool to
the specified temperature indicated in the ta-
ble.
e. Check the coolant temperature sensor for
continuity at the temperatures indicated in the
table.
B/L
B/L
2