Checking The Radiator Fan Motor; Checking The Coolant Temperature Sensor - Yamaha WR450F 2021 Owner's Service Manual

Resistor resistance
64.6–71.4 
a. Connect the digital circuit tester () to the
resistor as shown.
Digital circuit tester (CD732)
90890-03243
Model 88 Multimeter with tachom-
eter
YU-A1927
• Positive tester probe 
Black "1"
• Negative tester probe 
Black "2"
b. Measure the resistance of the resistor.
EAM30302

CHECKING THE RADIATOR FAN MOTOR

1. Check:
• Radiator fan motor
Faulty/rough movement  Replace.
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 move-
ment.
1
2
2
B
12V
8-69
ELECTRICAL COMPONENTS
EAM30303
CHECKING THE COOLANT TEMPERATURE
SENSOR
1. Remove:
• Coolant temperature sensor
EWA14130
WARNING
• Handle the coolant temperature sensor
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
2513–2777  at 20 C (2513–
2777  at 68 F)
Coolant temperature sensor re-
sistance
210–221  at 100 C (210–221 
at 212 F)
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.
B/L
B/L
2