Snowmobile Yamaha FX10X, FX10RTX, FX10RTRX, FX10RTRAX, FX10MTX, FX10MTRX, FX10MTRAX. Manual - part 86

8-38

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ELEC

SIGNAL SYSTEM

BRAKE LIGHT SWITCH

1. Disconnect:

• Brake light switch coupler

2. Connect:

• Pocket tester

(to the brake light switch coupler)

3. Check:

• Brake light switch continuity

Faulty 

→ Replace.

Switch position

Continuity

Brake lever operates

Yes

Brake lever does not 
operate

No

L/R

G

DC BACK BUZZER (FX10/FX10RTR/
FX10RTRA/FX10MTR/FX10MTRA)

1. Disconnect:

• DC back buzzer coupler 

2. Connect:

• Battery 

(to the DC back buzzer coupler)

3. Check:

• DC back buzzer

Does not sound 

→ Replace.

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ELEC

SIGNAL SYSTEM

COOLANT TEMPERATURE SENSOR

1. Remove the coolant temperature sensor.

CAUTION:

Handle the coolant temperature sensor with
special care. Never subject it to shock or allow
it to be dropped. If it is dropped, it must be
replaced.

2. Connect:

• Pocket tester 1 

(to the coolant temperature sensor)

NOTE:

Set the tester selector to the “

Ω × 1k” position.

3. Immerse the coolant temperature sensor 2 in

coolant  3 and check the coolant temperature
sensor operation.

4 Thermometer

CAUTION:

Never heat the coolant to a temperature of
120 °C (248 °F) or more.

4. If the coolant temperature sensor operation is

defective, replace it.

5. Install the coolant temperature sensor.

CAUTION:

Do not overtighten the coolant temperature
sensor.

Coolant temperature sensor resis-
tance:

5.21 ~ 6.37 k

Ω at 0 °C (32 °F) 

0.290 ~ 0.354 k

Ω at 80 °C (176 °F)

T

 

R

.

.

Coolant temperature sensor:

23 Nm (2.3 m · kg, 17 ft · lb)

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ELEC

SIGNAL SYSTEM

OIL LEVEL SWITCH

1. Remove:

• Oil level switch 

2. Connect:

• Pocket tester

(to the oil level switch coupler)

3. Check:

• Oil level switch continuity

Faulty 

→ Replace.

: Continuity

: No continuity

Switch position

Good 

condition

Bad condition

È

Down 
position

É Up position

Ch R/B

È

É

FUEL SENDER

1. Remove:

• Fuel sender 

(from the fuel tank) 

2. Connect:

• Pocket tester

(to the fuel sender coupler)

3. Measure:

• Fuel sender resistance (full 

a)

• Fuel sender resistance (empty 

b)

Out of specification 

→ Replace.

Fuel sender resistance (full):

10 ~ 12 

Ω at 20 °C (68 °F)

Fuel sender resistance (empty):

179 ~ 185 

Ω at 20 °C (68 °F)

B

G

a

b

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ELEC

SIGNAL SYSTEM

SPEED SENSOR

1. Inspect:

• Speed sensor

Inspection steps:

• Connect the pocket tester (DC 20 V) to the

speed sensor coupler (wire harness side) as
shown.

• Elevate the track and slowly rotate it.
• Measure the voltage (DC 5 V) of white and

black/blue. With each full rotation of the track
the voltage reading should cycle from 0.6 V to
4.8 V to 0.6 V to 4.8 V.
Out of specification 

→ Replace.

Positive tester probe 

→ White

Negative tester probe 

→ Black/Blue

Positive battery terminal 

→ Blue

Negative battery terminal 

→ Black/Blue