Yamaha YZF-R125 Service Manual: Faulty lighting or signaling system

Headlight does not come on

- Wrong headlight bulb

- Too many electrical accessories

- Hard charging

- Incorrect connection

- Improperly grounded circuit

- Poor contacts (main or light switch)

- Burnt-out headlight bulb

Headlight bulb burnt out

- Wrong headlight bulb

- Faulty battery

- Faulty rectifier/regulator

- Improperly grounded circuit

- Faulty main switch

- Faulty light switch

- Headlight bulb life expired

Tail/brake light does not come on

- Too many electrical accessories

- Incorrect connection

- Burnt-out tail/brake light LED

Turn signal does not come on

- Faulty turn signal switch

- Faulty turn signal relay

- Burnt-out turn signal bulb

- Incorrect connection

- Damaged or faulty wire harness

- Improperly grounded circuit

- Faulty battery

- Blown, damaged or incorrect fuse

Turn signal blinks slowly

- Faulty turn signal relay

- Faulty main switch

- Faulty turn signal switch

- Incorrect turn signal bulb

Turn signal remains lit

- Faulty turn signal relay

- Burnt-out turn signal bulb

Turn signal blinks quickly

- Incorrect turn signal bulb

- Faulty turn signal relay

- Burnt-out turn signal bulb

Horn does not sound

- Improperly adjusted horn

- Damaged or faulty horn

- Faulty main switch

- Faulty horn switch

- Faulty battery

- Blown, damaged or incorrect fuse

- Faulty wire harness

WIRING DIAGRAM

YZF-R125 2008

1. AC magneto

2. Crankshaft position sensor

3. Rectifier/regulator

4. Main fuse

5. Main switch

6. Radiator fan motor fuse

7. Clutch switch

8. Sidestand switch

9. Battery

10. Starter relay

11. Starter motor

12. Starting circuit cut-off relay

13. Diode

14.Neutral switch

15. Right handlebar switch

16. Start switch

17.Engine stop switch

18. Throttle body sensor assembly

19. Intake air pressure sensor

20. Intake air temperature sensor

21. Throttle position sensor

22.Coolant temperature sensor

23.Lean angle sensor

24. Self-diagnosis signal connector

25.ECU (engine control unit)

26. Ignition coil

27.Spark plug

28. FID (fast idle solenoid)

29.Fuel injector

30.Fuel pump

31.Fuel sender

32. Radiator fan motor relay

33. Radiator fan motor

34. Rear brake light switch

35. Front brake light switch

36. License plate light

37. Tail/brake light

38. Rear right turn signal light

39. Rear left turn signal light

40. Front right turn signal light

41. Front left turn signal light

42. Turn signal relay

43.Horn

44.Headlight relay

45.Left handlebar switch

46.Pass switch

47. Dimmer switch

48.Horn switch

49. Turn signal switch

50. Right headlight assembly

51.Headlight (low beam)

52.Auxiliary light

53.Left Headlight assembly

54.Headlight (high beam)

55.Meter assembly

56. Multi-function meter

57.Tachometer

58.Meter light

59.Coolant temperature warning light

60.High beam indicator light

61.Turn signal indicator light

62.Neutral indicator light

63.Engine trouble warning light

64. Ignition fuse

65.Headlight fuse

66.Signaling system fuse

67.Speed sensor

COLOR CODE

B Black

Br Brown

Ch Chocolate

Dg Dark green

G Green

Gy Gray

L Blue

O Orange

P Pink

R Red

Sb Sky blue

W White

Y Yellow

B/R Black/Red

B/W Black/White

B/Y Black/Yellow

Br/L Brown/Blue

Br/W Brown/White

G/B Green/Black

G/R Green/Red

G/W Green/White

G/Y Green/Yellow

Gy/B Gray/Black

Gy/R Gray/Red

L/B Blue/Black

L/R Blue/Red

L/W Blue/White

L/Y Blue/Yellow

O/B Orange/Black

O/W Orange/White

P/W Pink/White

R/B Red/Black

R/L Red/Blue

R/W Red/White

R/Y Red/Yellow

Sb/W Sky blue/White

W/B White/Black

Y/B Yellow/Black

Y/G Yellow/Green

Y/L Yellow/Blue

Y/R Yellow/Red

Y/W Yellow/White