Yamaha YFM660 01 User Manual

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–+ELECSIGNAL SYSTEM
CHECKING THE SIGNAL SYSTEM
1.If the tail/brake light fails to come on:
CONTINUITY 1.Bulb and bulb socket

Check the bulb and bulb socket for continu-
ity.
NO CONTINUITY
Replace the bulb and/or bulb socket.
CONTINUITY 2.Brake switches
Refer to “CHECKING THE SWITCH”.
NO CONTINUITY
Replace the brake switch.
3.Voltage

Connect the pocket tester (DC 20V) to the
bulb socket coupler.
Tester (+) lead → Yellow terminal 1 
Tester (–) lead → Black terminal 2 
MEETS
SPECIFICATION

Turn the...

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–+ELECSIGNAL SYSTEM
EB806024
2.If the neutral indicator light fails to come on:
CONTINUITY 1.Bulb and bulb socket

Check the bulb and bulb socket for continu-
ity.
NO CONTINUITY
Replace the bulb and/or bulb socket.
CONTINUITY 2.Neutral switch
Refer to “CHECKING THE SWITCH”.
NO CONTINUITY
Replace the neutral switch.
3.Voltage

Connect the pocket tester (DC 20V) to the
bulb socket coupler.
Tester (+) lead → Brown terminal 1 
Tester (–) lead → Sky blue terminal 2 
MEETS
SPECIFICATION

Turn the main...

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–+ELECSIGNAL SYSTEM
3.If the reverse indicator light fails to come on:
CONTINUITY 1.Bulb and bulb socket

Check the bulb and bulb socket for continu-
ity.
NO CONTINUITY
Replace the bulb and/or bulb socket.
CONTINUITY 2.Reverse switch
Refer to “CHECKING THE SWITCH”.
NO CONTINUITY
Replace the reverse switch.
3.Voltage

Connect the pocket tester (DC 20V) to the
bulb socket coupler.
Tester (+) lead → Brown terminal 1 
Tester (–) lead → Green/Blue terminal 2 
MEETS
SPECIFICATION

Turn the main switch...

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–+ELECSIGNAL SYSTEM
4.If the coolant temperature warning light does not come on when the start switch is pushed on, or if
the coolant temperature warning light does not come on when the temperature is high (more than
117 ~ 123 °C (242.6 ~ 253.4 °F)):
CONTINUITY 1.Bulb and bulb socket

Check the bulb and bulb socket for continu-
ity. 
NO CONTINUITY
Replace the bulb and/or bulb socket.
GOOD
CONDITION 2.Thermo switch 2

Remove the thermo switch from the ther-
mostat housing.

Connect the pocket...

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–+ELECSIGNAL SYSTEM
C0NTINUITY
3.Voltage

Connect the pocket tester (DC 20V) to the
bulb socket coupler. 
Tester (+) lead → Red/Black terminal 1 
Tester (–) lead → White/Blue terminal 2 
*
MEETS
SPECIFICATION

Turn the main switch to “ON”.

Check the voltage (12 V).
OUT OF SPECIFICATION
The wiring circuit from the main switch to the
bulb socket connector is faulty, repair it.
CORRECT 4.Diode
 Remove the diode from the coupler.
 Connect the pocket tester (Ω
 ×
 1) to the
diode terminals as...

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–+ELECSIGNAL SYSTEM
C0NTINUITY
CORRECT 5.Start switch
Refer to “CHECKING THE SWITCH”.
This circuit is not faulty.
*
INCORRECT 
Replace the handlebar switch (left). 

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–+ELECCOOLING SYSTEM
COOLING SYSTEM
CIRCUIT DIAGRAM
3Main switch
4Battery
5Fuse
DCircuit breaker (fan motor)
EThermo switch 1
FFan motor 

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–+ELECCOOLING SYSTEM
TROUBLESHOOTING 
Procedure
Check:
1.Fuse
2.Battery
3.Main switch
4.Fan motor
5.Circuit breaker (fan motor)IF THE FAN MOTOR DOES NOT MOVE:
6.Thermo switch 1
7.Wiring connection
(the entire cooling system)
OTE:

Remove the following part(s) before trouble-
shooting.
1)Seat
2)Front fender

Use the following special tool(s) for trouble-
shooting.
Pocket tester:
P/N. YU-03112, 90890-03112
EB802011
CONTINUITY 1.Fuse
Refer to “CHECKING THE SWITCH”.
NO CONTINUITY
Replace the fuse....

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–+ELECCOOLING SYSTEM
C0NTINUITY
TURNS 4.Fan motor

Disconnect the fan motor coupler.

Connect the battery (12 V) as shown.
Battery (+) lead → Blue terminal 1 
Battery (–) lead → Black terminal 2 

Check the operation of the fan motor.
*
DOES NOT TURN
Replace the fan motor.
MEETS
SPECIFICATION 5.Circuit breaker (fan motor)

Remove the circuit breaker from the wire
harness.

Connect the pocket tester (Ω
 ×
 1) to the cir-
cuit breaker.
Circuit breaker resistance:
Zero Ω at 20 °C (68 °F)
*
OUT OF...

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–+ELECCOOLING SYSTEM
C0NTINUITY
GOOD
CONDITION 6.Thermo switch 1

Remove the thermo switch from the radia-
tor.

Connect the pocket tester (Ω
 ×
 10) to the
thermo switch 1
.

Immerse the thermo switch in coolant 2
.

Check the thermo switch for continuity.
While heating the coolant use a thermome-
ter 3
 to record the temperatures.
Test 
stepWater temperature
Good 
condition
Thermo switch
10 ~ 92 ± 3 °C
(32 ~ 197.6 ± 5.4 °F)
×
2More than 98 ± 3 °C 
(208.4 ± 5.4 °F)
3*98 ± 3 to 92 ± 3 °C 
(208.4 ±...