Yamaha MT-03 Service Manual page 384

EAS28180
CHECKING THE HORN
1. Check:
• Horn resistance
Out of specification
Coil resistance
1.15–1.25 Ω at 20 °C (68 °F)
a. Disconnect the horn leads from the horn ter-
minals.
b. Connect the pocket tester (Ω x 1) to the horn
terminals.
Pocket tester
90890-03112
• Positive tester probe
• Negative tester probe
c. Measure the horn resistance.
2. Check:
• Voltage
a. Disconnect the horn leads from the horn ter-
minals.
b. Connect the pocket tester (DC 20 V) to the
horn leads.
Pocket tester
90890-03112
• Positive tester probe
• Negative tester probe
c. Set the main switch to "ON".
d. Push the horn switch.
e. Measure the voltage (DC 12 V) of pink at the
horn terminal.
Replace.
horn terminal
horn terminal
pink "1"
ground
ELECTRICAL COMPONENTS
3. Check:
• Horn sound
Faulty sound
a. Disconnect the horn leads from the horn ter-
minals.
b. Connect a battery (12 V) to the horn termi-
nals.
EAS28210
CHECKING THE COOLANT
TEMPERATURE SENSOR
1. Remove:
• Coolant temperature sensor
(from the engine)
WARNING
• Handle the coolant temperature sensor
with special care.
• Never subject the coolant temperature
sensor to strong shocks. If the coolant
temperature sensor is dropped, replace it.
2. Check:
• Coolant temperature sensor resistance
Out of specification
Coolant temperature sensor
resistance
2.28-2.63 kΩ at 20 °C (68 °F)
0.305-0.331 kΩ at 80 °C (176 °F)
0.138-0.145 kΩ at 110 °C (230 °F)
a. Connect the pocket tester (Ω x 1k) to the
coolant temperature sensor terminal as shown.
Pocket tester
90890-03112
3
b. Immerse the coolant temperature sensor "1"
in a container filled with water "2".
8-57
Replace the horn.
Replace.
1
2