Yamaha YZF-R125 Service Manual: Electrical components
1. Main switch
2. Clutch switch
3. Front brake light switch
4. Ignition coil
5. Throttle body sensor assembly (intake air pressure sensor, intake air temperature sensor, throttle position sensor)
6. FID (fast idle solenoid)
7. Rectifier/regulator
8. Lean angle sensor
9. Starting circuit cut-off relay
10.Turn signal relay
11.Radiator fan motor relay
12.Headlight relay
13.ECU (engine control unit)
14.Fuse box
15.Starter relay
16.Battery
17.Rear brake light switch
18.Sidestand switch
19.Neutral switch
20.Crankshaft position sensor
21.Coolant temperature sensor
22.Speed sensor
23.Radiator fan
24.Horn
- Checking the switches
- Checking the bulbs and bulb sockets
- Checking the fuses
- Checking and charging the battery
- Checking the relays
- Checking the turn signal relay
- Checking the diode
- Checking the spark plug cap
- Checking the ignition coil
- Checking the ignition spark gap
- Checking the crankshaft position sensor
- Checking the lean angle sensor
- Checking the starter motor operation
- Checking the stator coil
- Checking the rectifier/regulator
- Checking the horn
- Checking the fuel sender
- Checking the speed sensor
- Checking the radiator fan motor
- Checking the coolant temperature sensor
- Checking the throttle body sensor assembly
- Checking the fid (fast idle solenoid)
Troubleshooting
If the fuel pump fails to operate.
NOTE:
Before troubleshooting, remove the following part(s):
1. Rider seat
2. Fuel tank
...
Checking the switches
1. Clutch switch
2. Main switch
3. Front brake light switch
4. Sidestand switch
5. Rear brake light switch
6. Neutral switch
7. Turn signal switch
8. Horn switch
9. Dimmer switch
10.Pass ...
Other materials:
Checking the relays
Check each switch for continuity with the pocket
tester. If the continuity reading is incorrect, replace
the relay.
1. Disconnect the relay from the wire harness.
2. Connect the pocket tester ( × 1) and battery
(12 V) to the relay terminal as shown.
Check the relay operation.
Out ...
Installing the relay arm
1. Lubricate:
Spacers
Bearings
Oil seals
Bolts (unthreaded shaft portion only)
2. Install:
Bearing "1"
(to the relay arm)
Oil seal "2"
(to the relay arm)
3. Rear shock absorber assembly
4. Relay arm
5. Connecting arm
A. Left side
B. Right side ...
Preparation for removal and disassembly
1. Before removal and disassembly, remove all
dirt, mud, dust and foreign material.
2. Use only the proper tools and cleaning equipment.
Refer to "SPECIAL TOOLS" on page 1-8.
3. When disassembling, always keep mated
parts together. This includes gears, cylinders,
pistons and other part ...