Yamaha 2003 YFZ450S, Service Manual

Page: 360 / 375

8 - 37
– +
ELEC
SIGNAL SYSTEM
YES
NO
2. Thermo switch 2
• Remove the thermo switch 2 from the radi-
ator.
• Connect the pocket tester (
Ω ×
1) to the
thermo switch 2
1
as shown.
• Immerse the thermo switch 2 in a con-
tainer filled with coolant
2
.
• Place a thermometer
3
in the coolant.
• Slowly heat the coolant, then let it cool
down to the specified temperature.
• Check the thermo switch 2 for continuity at
the temperatures indicated below.
Test step
Coolant temperature Continu-
ity
Thermo switch
1
Less than 120
±
3 °C
(248
±
5.4 °F)
NO
2
More than 120
±
3 °C
(248
±
5.4 °F)
YES
3*
More than 115
±
3 °C
(239
±
5.4 °F)
YES
4*
Less than 115
±
3 °C
(239
±
5.4 °F)
NO
Steps 1 & 2: Heating phase
Steps 3* & 4*: Cooling phase
È
The thermo switch circuit is open and the cool-
ant temperature warning light is off.
É
The thermo switch circuit is closed and the
coolant temperature warning light is on.
WARNING
_
• Handle the thermo switch with special
care.
• Never subject the thermo switch to
strong shocks. If the thermo switch is
dropped, replace it.
T
R
.
.
Thermo switch
28 Nm (2.8 m · kg, 20 ft · lb)
• Does the thermo switch 2 operate properly
as described above?
Replace the thermo
switch 2.
É
È
115 ± 3 ˚C
(239 ± 5.4 ˚F)
120 ± 3 ˚C
(248 ± 5.4 ˚F)