2004 YAMAHA YZF-R1S light

8-29
YESNO

Clean the battery
terminals.

Recharge or re-
place the battery.
EAS00749
3. Main switch

Check the main switch for continuity.
Refer to “CHECKING THE SWITCHES”.

Is the main switch OK?
YESNO
Replace the main
switch.
EAS00784
YESNO 4. Dimmer switch

Check the dimmer switch for continuity.
Refer to “CHECKING THE SWITCHES”.

Is the dimmer switch OK?
The dimmer switch is
faulty. Replace the
left handlebar switch.
Minimum open-circuit voltage
12.8 V or more at 20C (68F)

Is the battery OK?
LIGHTING SYSTEMELEC
NOTE:
YESNO
1. Main, turn and headlight fuses

Check the main, turn and headlight fuses for
continuity.
Refer to “CHECKING THE FUSES” in chap-
ter 3.

Are the main, turn and headlight fuses OK?
Replace the fuse(s).
2. Battery

Check the condition of the battery.
Refer to “CHECKING AND CHARGING
THE BATTERY” in chapter 3.
EAS00739EAS00781
TROUBLESHOOTING
Any of the following fail to light: headlight,
high beam indicator light, taillight, licence
light or meter light.
Check:
1. main, turn and headlight fuses
2. battery
3. main switch
4. dimmer switch
5. pass switch
6. headlight relay (on / off)
7. headlight relay (dimmer)
8. wiring connections
(of the entire lighting system)

Before troubleshooting, remove the following
part(s):
1. seat
2. fuel tank
3. side cowlings

Troubleshoot with the following special tool(s).
Pocket tester
90890-03112, YU-3112
EAS00738
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8-30

Does the Headlight relay (dimmer) have
continuity between red / yellow and
black / green ?
NOYES
Replace the dimmer
relay. Positive tester probe
red / yellow
Negative tester probe
black / green
1
2
3
4
5. Headlight relay (on / off)

Disconnect the headlight relay (on / off) from
the coupler.

Connect the pocket tester (Ω
1) and bat-
tery (12 V) to the headlight relay (on / off) as
shown.
Positive battery lead
red / yellow
Negative battery lead
yellow / black
EAS00787
YESNO 7. Wiring

Check the entire lighting system’s wiring.
Refer to “CIRCUIT DIAGRAM”.

Is the lighting system’s wiring properly con-
nected and without defects?
Properly connect or
repair the lighting
system’s wiring.
Check the condition
of each of the lighting
system’s circuits.
Refer to “CHECK-
ING THE LIGHTING
SYSTEM”.

Does the headlight relay (dimmer) have
continuity between black / green and
black / yellow ?
Positive tester probe
black / green
Negative tester probe
black / yellow
1
2
3
4
6. Headlight relay (dimmer)

Disconnect the headlight relay (dimmer)
from the coupler.

Connect the pocket tester (Ω
1) and bat-
tery (12 V) to the headlight relay (dimmer) as
shown.
Positive battery lead
black
Negative battery lead
yellow
3
4
3
4
YESNO
Replace the head-
light relay (dimmer).
LIGHTING SYSTEMELEC
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8-31
High beam indicator light (LEDs)
Positive tester probe
black / yellow
Negative tester probe

black / white
YESNO 1. Headlight bulb and socket

Check the headlight bulb and socket for con-
tinuity.
Refer to “CHECKING THE BULBS AND
BULB SOCKETS”.

Are the headlight bulb and socket OK?
Replace the head-
light bulb, socket or
both.
YESNO 2. Voltage

Connect the pocket tester (DC 20 V) to the
headlight and meter assembly couplers as
shown.
The wiring circuit
from the main switch
to the headlight cou-
pler is faulty and
must be repaired.
When the dimmer switch is set to “ ”
When the dimmer switch is set to “ ”
Headlight coupler (wire harness side)
Low beam
Headlight
Positive tester probe
black
Negative tester probe
black / green
1
2
Meter assembly coupler (wire harness side)

Turn the main switch to “ON”.

Start the engine.

Set the dimmer switch to “ ” or “ ”.

Measure the voltage (DC 12 V) of
black / green or black / yellow on the
headlight coupler (wire harness side).

Is the voltage within specification?
2
This circuit is OK.
A
B
Headlight
Positive tester probe
black
Negative tester probe
black / yellow
A
Headlight coupler (wire harness side)
High beam
B
6
5
3
4
4
LIGHTING SYSTEMELEC
EAS00788
CHECKING THE LIGHTING SYSTEM
1. The headlight and the high beam indicator
light fail to come on.
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8-32
LIGHTING SYSTEMELEC
YESNO 1. License plate light bulb and socket

Check the license plate light bulb and socket
for continuity.
Refer to “CHECKING THE BULBS AND
BULB SOCKETS”.

Are the license plate light bulb and socket
OK?
Replace the license
plate light bulb, sock-
et or both.
EAS007922. The license plate light fails to come on.
YESNO 2. Voltage

Connect the pocket tester (DC 20 V) to the
license plate light coupler (wire harness light
side) as shown.
The wiring circuit
from the main switch
to the license plate
light coupler is faulty
and must be re-
paired. Positive tester probe
blue / red
Negative tester probe
black
1
2

Turn the main switch to “ON”.

Measure the voltage (DC 12 V) of blue / red
on the license plate light coupler (wire
harness side).

Is the voltage within specification?
1
This circuit is OK.
EAS00790
3. The tail / brake light fails to come on.
YESNO 1. Voltage

Connect the pocket tester (DC 20 V) to the
tail / brake light coupler (wire harness side)
as shown.
Wiring circuit from
the main switch to
the tail / brake light
coupler is faulty and
must be repaired. Positive tester probe
blue / red
Negative tester probe
black
1
2

Turn the main switch to “ON”.

Measure the voltage (DC 12 V) of blue / red
on the tail / brake light coupler (wire har-
ness side).

Is the voltage within specification?
1
This circuit is OK.
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8-33
LIGHTING SYSTEMELEC
EAS00791
4. The auxiliary light fails to come on.
YESNO 1. Auxiliary light and socket

Check the auxiliary light bulb and socket for
continuity.
Refer to “CHECKING THE BULBS AND
BULB SOCKETS”.

Are the auxiliary light .bulb and socket OK?
Replace the auxiliary
light bulb, socket or
both.
YESNO 2. Voltage

Connect the pocket tester (DC 20 V) to the
auxiliary light coupler (auxiliary light side) as
shown.
The wiring circuit
from the main switch
to the auxiliary light
coupler is faulty and
must be repaired. Positive tester probe
blue / red
Negative tester probe
black
1

Turn the main switch to “ON”.

Measure the voltage (DC 12 V) of blue / red
on the auxiliary light coupler (auxiliary
light side).

Is the voltage within specification?
2
This circuit is OK.
2
5. The turn signa l/ position light fails to come on.
YESNO 1. Turn signal / position light and socket

Check the turn signal / position light bulb and
socket for continuity.
Refer to “CHECKING THE BULBS AND
BULB SOCKETS”.

Are the turn signal / position light bulb and
socket OK?
Replace the turn sig-
nal / position light
bulb, socket or both.
YESNO 2. Voltage

Connect the pocket tester (DC 20 V) to the
turn signal / position light coupler (wire har-
ness side) as shown.
The wiring circuit from
the main switch to the
turn signal / position
light coupler is faulty
and must be repaired.
Turn the main switch to “ON”.

Measure the voltage (DC 12 V) of blue or
blue on the turn signal / position light cou-
pler (wire harness side).

Is the voltage within specification?
3
This circuit is OK.
Left turn signal / position light
Positive tester probe
blue
Negative tester probe
black
Right turn signal / position light
Positive tester probe
blue
Negative tester probe
black
1
2
A
Left turn signal / position light
Right turn signal / position light
B
A
B
3
4
1
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8-35
SIGNALING SYSTEMELEC
1Main switch
4Fuse (main)
6Battery
10Starting circuit cut-off relay
11Neutral switch
13Fuel pump
14E.C.U.
27Speed sensor
38Fuel level warning light
39Oil level warning light
40Neutral indicator light
41Tachometer
42Shift timing indicator light
43Multi function meter
45Coolant temperature indicator light
47Turn signal indicator light (left)
48Turn signal indicator light (light)
55Turn signal relay
58Horn switch
60Turn signal switch
61Horn
62Front turn signal / position light (left)
63Front turn signal / position light (right)
64Rear turn signal light (left)
65Rear turn signal light (right)
73Fuse (ignition)
74Fuse (signal)
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8-36
YESNO

Clean the battery
terminals.

Recharge or re-
place the battery.
EAS00749
3. Main switch

Check the main switch for continuity.
Refer to “CHECKING THE SWITCHES”.

Is the main switch OK?
YESNO
Replace the main
switch.
YESNO 1. Horn switch

Check the horn switch for continuity.
Refer to “CHECKING THE SWITCHES”.

Is the horn switch OK?
Replace the left han-
dlebar switch.
EAS00796
CHECKING THE SIGNALING SYSTEM
1. The horn fails to sound.
EAS00795
4. Wiring

Check the entire signaling system’s wiring.
Refer to “CIRCUIT DIAGRAM”.

Is the signaling system’s wiring properly
connected and without defects?
YESNO
Properly connect or
repair the signaling
system’s wiring.
Check the condition
of each of the signal-
ing system’s circuits.
Refer to “CHECK-
ING THE LIGHTING
SYSTEM”.
SIGNALING SYSTEMELEC
NOTE:
YESNO
1. Backup, main, ignition, signal and park
fuses

Check the backup, main, ignition, signal and
park fuses for continuity.
Refer to “CHECKING THE FUSES” in chap-
ter 3.

Are the backup, main, ignition, signal and
park fuses OK?
Replace the fuse(s).
2. Battery

Check the condition of the battery.
Refer to “CHECKING AND CHARGING
THE BATTERY” in chapter 3.
Minimum open-circuit voltage
12.8 V or more at 20C (68F)

Is the battery OK?
EAS00739EAS00794
TROUBLESHOOTING

Any of the following fail to light: turn sig-
nal light, brake light or an indicator light.

The horn fails to sound.
Check:
1. backup, main, ignition, signal, and park
fuses
2. battery
3. main switch
4. wiring connections
(of the entire signaling system)

Before troubleshooting, remove the following
part(s):
1. seat
2. fuel tank
3. side cowlings

Troubleshoot with the following special tool(s).
Pocket tester
90890-03112, YU-3112
EAS00738
ProCarManuals.com

8-37
SIGNALING SYSTEMELEC
YESNO 1. Tail / brake light bulb and socket

Check the tail / brake light bulb and socket for
continuity.
Refer to “CHECKING THE BULBS AND
BULB SOCKETS”.

Are the tail / brake light bulb and socket OK?
Replace the tail /
brake light bulb,
socket or both.
EAS007972. The tail / brake light fails to come on.
YESNO 2. Brake light switches

Check the brake light switches for continuity.
Refer to “CHECKING THE SWITCHES”.

Is the brake light switch OK?
Replace the brake
light switch.
3. Voltage

Connect the pocket tester (DC 20 V) to the
tail / brake light coupler (wire harness side)
as shown.
Positive tester probe
yellow
Negative tester probe
black
1
2

Turn the main switch to “ON”.

Pull in the brake lever or push down on the
brake pedal.

Measure the voltage (DC 12 V) of yellow
on the tail / brake light coupler (wire harness
side).

Is the voltage within specification?
1
YESNO 2. Voltage

Connect the pocket tester (DC 20 V) to the
horn connector at the horn terminal as
shown.
The wiring circuit
from the main switch
to the horn connec-
tor is faulty and must
be repaired. Positive tester probe
black / white
Negative tester probe
ground
1

Turn the main switch to “ON”.

Push the horn switch.

Measure the voltage (DC 12 V) of
black / white at the horn terminal.

Is the voltage within specification?
NOYES 3. Horn

Disconnect the black connector at the horn
terminal.

Connect a jumper lead to the horn termi-
nal and ground the jumper lead.

Turn the main switch to “ON”.

Push the horn switch.

Does the horn sound?
The horn is OK.
1
Replace the horn.
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