Yamaha MT-03 - Service manual > Electric starting system

Circuit diagram

3. Neutral switch

4. Main switch

7. Battery

8. Main fuse

9. Starter relay

10.Starter motor

12.Relay unit

13.Starting circuit cut-off relay

38.Sidestand switch

41.Engine stop switch

42.Start switch

45.Clutch switch

67.Ignition fuse

Starting circuit cut-off system operation

If the engine stop switch is set to "I" and the main switch is turned "ON" (both switch circuits are closed), the starter motor can only operate if at least one of the following conditions is met:

• The transmission is in neutral (the neutral switch circuit is closed).
• The clutch lever is pulled to the handlebar (the clutch switch circuit is closed) and the sidestand is up (the sidestand switch circuit is closed).

The starting circuit cut-off relay prevents the starter motor from operating when neither of these conditions has been met. In this instance, the starting circuit cut-off relay stays open so current cannot reach the starter motor. When at least one of the above conditions has been met, the starting circuit cut-off relay is closed and the engine can be started by pushing the start switch "".

WHEN THE TRANSMISSION IS IN NEUTRAL

WHEN THE SIDESTAND IS UP AND THE CLUTCH LEVER IS PULLED TO THE HANDLEBAR

1. Battery
2.  Main fuse
3. Main switch
4. Ignition fuse
5. Engine stop switch
6. Relay unit (starting circuit cut-off relay)
7. Relay unit (diode)
8. Clutch switch
9. Sidestand switch
10. Neutral switch
11. Start switch
12. Starter relay
13. Starter motor

Troubleshooting

The starter motor fails to turn.

NOTE:

Before troubleshooting, remove the following part(s):

1. Seats
2. Side panels (left and right)
3. Fuel tank
4. Battery cover

Charging system

Circuit diagram

2. A.C. magneto

5. Rectifier/regulator

7. Battery

8. Main fuse

Troubleshooting

The battery is not being charged.

NOTE:

• Before troubleshooting, remove the following part(s):

1. Seats
2.  Side panels (left and right)
3.  Fuel tank
4.  Battery cover

Lighting system

Circuit diagram

4. Main switch

7. Battery

8. Main fuse

22.ECU

32.High beam indicator light

44.Headlight relay

48.Dimmer switch

49.Pass switch

56.Headlight

58.Tail/brake light

59.Auxiliary light

64.Parking lighting fuse

65.Headlight fuse

Troubleshooting

Any of the following fail to light: headlight (high beam), headlight (low beam), high beam indicator light, taillight, license plate light, auxiliary light or meter light.

NOTE:

• Before troubleshooting, remove the following part(s):

1. Seats
2.  Side panels (left and right)
3.  Fuel tank
4. Battery cover
5. Headlight assembly

Signaling system

Circuit diagram

3. Neutral switch

4. Main switch

7. Battery

8. Main fuse

12.Relay unit

21.Coolant temperature sensor

22.ECU

23.Speed sensor

28.Neutral indicator light

29.Multi-function meter

30.Fuel level warning light

31.Turn signal indicator light

33.Coolant temperature warning light

36.Engine trouble warning light

37.Fuel pump

39.Front brake light switch

43.Turn signal/hazard relay

46.Hazard switch

47.Turn signal switch

50.Horn switch

52.Rear turn signal light (right)

53.Front turn signal light (right)

54.Front turn signal light (left)

55.Rear turn signal light (left)

57.Horn

58.Tail/brake light

61.Rear brake light switch

64.Parking lighting fuse

66.Signaling system fuse

67.Ignition fuse

69.Backup fuse (immobilizer unit, multi-function meter unit)

TROUBLESHOOTING

Any of the following fail to light: turn signal light, brake light or indicator light.

NOTE:

• Before troubleshooting, remove the following part(s):

1. Seats
2. Side panels (left and right)
3. Fuel tank
4. Battery cover
5. Headlight assembly

Checking the signaling system

Cooling system

Circuit diagram

4. Main switch

7. Battery

8. Main fuse

22.ECU

62.Radiator fan motor

63.Radiator fan motor relay

67.Ignition fuse

68.Radiator fan motor fuse

Troubleshooting

If the radiator fan motor fails to operate.

NOTE:

Before troubleshooting, remove the following part(s):

1. Seats

2. Side panels (left and right)

3. Fuel tank

4. Battery cover

See also: