electrical YAMAHA VX110 2005 User Guide

3-23
E
INSP
ADJ
ELECTRICAL
1. Remove:
Bands
Battery negative lead 1

Battery positive lead 2

Battery
Battery breather hose 3

WARNING
When removing the battery, disconnect
the negative lead first.
Remove the battery to prevent acid loss
during turning the watercraft on its side
for the impeller, etc.
2. Inspect:
Electrolyte level
Low →
Add distilled water.
The electrolyte level should be between
the maximum a
and minimum b
level
marks.
CAUTION:
Use only distilled water. Other types of
water contain minerals which are harmful
to batteries.Filling steps:
Remove each filler cap.
Add distilled water to the maximum level
mark.
When the electrolyte level reaches the
maximum level mark, allow the cell to
stand for 20 minutes. If the electrolyte
level drops, add more distilled water so
the level reaches the maximum level
mark.
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3-24
E
INSP
ADJ
ELECTRICAL
3. Inspect:
Specific gravity
Out of specification →
Charge.
4. Install:
Filler caps
CAUTION:
Before installation, rinse off any fluid from
the battery box and battery and make sure
that the battery is dry before installing it.
Specific gravity at 20 °C (68 °F):
1.28
Charging current:
1.9 A
× 10 h
5. Install:
Battery breather hose 1

Battery
Battery positive lead 2

Battery negative lead 3

Bands
CAUTION:
Connect the positive lead to the battery
terminal first.
Make sure the battery leads are con-
nected properly. Reversing the leads can
seriously damage the electrical system.
Make sure that the battery breather hose is
properly connected and is not obstructed.
Coat the terminals with a water resistant
grease to minimize terminal corrosion.
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4-12
EFUEL
THROTTLE BODY ASSEMBLY AND INTAKE
MANIFOLD
SERVICE POINTS
Fuel hose clamps removal
1. Remove:
Fuel hose clamps
CAUTION:
If the fuel hose clamps are removed with-
out cutting the joint first, the fuel hose will
be damaged.
Hose clamps installation
1. Install:
Fuel hose clamps
WARNING
Do not reuse the fuel hose clamps, always
replace them with new ones.
NOTE:
Crimp the fuel hose clamps properly to
securely fasten them.
Fuel hose disconnection
WARNING
Before disconnecting the hose, remove the
fuel tank filler cap to reduce any pressure
inside the fuel tank, and then disconnect
the battery negative lead to cut off the elec-
tric current to the electrical systems.
1. Wrap the quick connector with a cloth, and
then rotate the quick connector tab 1
to
the stopper position a
.
WARNING
If the quick connector is removed sud-
denly, pressurized fuel could spray out. To
gradually release the fuel pressure, be sure
to remove the quick connector slowly.
1
a
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E
–+ELEC
1
2
3
4
5
6
7
8
9
CHAPTER 7
ELECTRICAL SYSTEM
ELECTRICAL COMPONENTS........................................................................ 7-1
FUSE BOX ....................................................................................................... 7-2
EXPLODED DIAGRAM ............................................................................. 7-2
REMOVAL AND INSTALLATION CHART ................................................ 7-2
ECM AND RECTIFIER/REGULATOR............................................................. 7-7
EXPLODED DIAGRAM ............................................................................. 7-7
REMOVAL AND INSTALLATION CHART ................................................ 7-7
ELECTRICAL ANALYSIS ............................................................................... 7-9
INSPECTION............................................................................................. 7-9
Digital tester ........................................................................................ 7-9
Low resistance measurement ........................................................... 7-10
Peak voltage measurement .............................................................. 7-10
Peak voltage adapter ........................................................................ 7-11
Test harness .................................................................................... 7-11
IGNITION SYSTEM ....................................................................................... 7-12
WIRING DIAGRAM ................................................................................. 7-12
IGNITION SPARK ................................................................................... 7-14
IGNITION SYSTEM PEAK VOLTAGE .................................................... 7-15
BATTERY ................................................................................................ 7-17
FUSE ....................................................................................................... 7-17
SPARK PLUGS ....................................................................................... 7-17
IGNITION COIL ....................................................................................... 7-18
ENGINE STOP SWITCH ......................................................................... 7-18
ENGINE TEMPERATURE SENSOR ...................................................... 7-19
SENSOR ASSEMBLY ............................................................................. 7-19
THERMOSWITCH (ENGINE).................................................................. 7-20
THERMOSWITCH (EXHAUST) .............................................................. 7-21
MAIN AND FUEL PUMP RELAY............................................................. 7-22
ELECTRONIC CONTROL THROTTLE VALVE RELAY ......................... 7-23
THROTTLE POSITION SENSOR ........................................................... 7-24
ACCELERATOR POSITION SENSOR ................................................... 7-26
CAM POSITION SENSOR ...................................................................... 7-29
SLANT DETECTION SWITCH ................................................................ 7-30
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7-1
E
–+ELECELECTRICAL COMPONENTS
ELECTRICAL COMPONENTS
O
N
M
L
K
J
I
H
G
F
E
D
C
B
A
0
91
2
3
4
5
6
7
8
1Thermoswitch (engine)
2Fuse box
3Slant detection switch
4Starter motor
5Engine temperature sensor
6Spark plugs and ignition coils
7Cam position sensor
8Battery
9Speed sensor
0Sensor assembly (intake air
pressure and intake air tem-
perature)AOil pressure switch
BFuel injectors
CThermoswitch (exhaust)
DRectifier/regulator
EECM
FThrottle body assembly
GLighting coil and pickup coil
HEngine stop switch, engine
shut-off switch, and start
switch
ISteering sensor
JBuzzerKAccelerator position sensor
LElectric fuel pump
MFuel sender
NMultifunction meter
ORemote control unit (Deluxe
model only)
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7-9
E
–+ELECELECTRICAL ANALYSIS
ELECTRICAL ANALYSIS
INSPECTION
CAUTION:
All measuring instruments should be han-
dled with special care. Damaged or mis-
handled instruments will not measure
properly.
On an instrument powered by dry batter-
ies, check the battery’s voltage periodi-
cally and replace the batteries if
necessary.
Digital tester
NOTE:
Throughout this chapter the part numbers of
the specified digital testers have been omitted.
Refer to the following part numbers.
NOTE:
“” indicates a continuity of electricity;
i.e., a closed circuit at the respective switch
position.
Digital multimeter:
YU-34899-A
Digital circuit tester:
90890-03174
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7-10
E
–+ELECELECTRICAL ANALYSIS
Low resistance measurement
NOTE:
When measuring a resistance of 10 Ω
or less
using a digital tester, the correct measure-
ment cannot be obtained because of the
tester’s internal resistance.
To obtain the correct value, subtract the
internal resistance from the displayed mea-
surement.
The internal resistance of the tester can be
obtained by connecting both of its terminals.
Correct value =
Displayed measurement –
Internal resistance
Peak voltage measurement
NOTE:
When checking the condition of the ignition
system it is vital to know the peak voltage.
Cranking speed is dependant on many fac-
tors (e.g., fouled or weak spark plugs, a
weak battery). If one of these is defective,
the peak voltage will be lower than specifica-
tion.
If the peak voltage measurement is not
within specification the engine will not oper-
ate properly.
A low peak voltage will also cause compo-
nents to prematurely wear.
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7-11
E
–+ELECELECTRICAL ANALYSIS
Peak voltage adapter
NOTE:
Throughout this chapter the part numbers of
the specified peak voltage adapters have
been omitted. Refer to the following part
numbers.
The peak voltage adapter should be used
with a digital tester.
When measuring the peak voltage, connect
the peak voltage adapter to the digital circuit
tester and switch the selector to the DC volt-
age mode.
NOTE:
Make sure that the adapter leads are prop-
erly installed in the digital circuit tester.
Make sure that the positive pin (the “+” mark
facing up as shown) on the adapter is
installed into the positive terminal of the
tester.
The test harness is needed for the following
tests.
È Voltage measurement
É Peak voltage measurement
Test harness
NOTE:
If the lighting coil and pickup coil(s) are mea-
sured unloaded, disconnect the test harness
on the output side coupler.
Peak voltage adapter:
YU-39991
Peak voltage adapter B:
90890-03172
Checking steps:
Disconnect the coupler connections.
Connect the test harness between the
couplers.
Connect the tester terminals to the termi-
nals which are being checked.
Run the engine and observe the mea-
surement.È
É
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7-15
E
–+ELECIGNITION SYSTEM
IGNITION SYSTEM PEAK VOLTAGE
WARNING
When checking the electrical components,
do not touch any of the connections of the
digital tester lead wires.
NOTE:
If there is no spark, or the spark is weak,
continue with the ignition system test.
If a good spark is obtained, the problem is
not with the ignition system, but possibly with
the spark plug(s) or another component.
1. Measure:
ECM output peak voltage
Below specification →
Measure the
pickup coil output peak voltage.
NOTE:
When measuring the ECM output peak volt-
age while cranking the engine, disconnect
the ignition coil couplers for all cylinders
except for the cylinder being measured.
To crank the engine, connect the engine
shut-off cord (lanyard) to the engine shut-off
switch, and then press the start switch.
Test harness (2 pins):
New: YB-06867
Current: YB-06767
Test harness FWY-2 (2 pins):
New: 90890-06867
Current: 90890-06767
ECM output peak voltage:
Black/red (B/R) –
Red/yellow (R/Y)
Black/white (B/W) –
Red/yellow (R/Y)
Black/yellow (B/Y) –
Red/yellow (R/Y)
Black/green (B/G) –
Red/yellow (R/Y)
r/minLoaded
Cranking 2,000 3,500
V 90 130 140
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7-17
E
–+ELEC
NOTE:
To crank the engine, connect the engine shut-
off cord (lanyard) to the engine shut-off switch,
and then press the start switch and engine
stop switch simultaneously.
4. Measure:
Rectifier/regulator output voltage
Below specification →
Replace the recti-
fier/regulator.
NOTE:
Do not use the peak voltage adapter to mea-
sure the output voltage.
Disconnect the output lead of the tester har-
ness.
Test harness (6 pins):
YB-06848
Test harness FSW-6A (6 pins):
90890-06848
Rectifier/regulator output
voltage:
Red (R) – Black (B)
r/minUnloaded
3,500
V 13.0
BATTERY
Refer to “ELECTRICAL” in Chapter 3.
FUSE
Refer to “STARTING SYSTEM”.
SPARK PLUGS
Refer to “POWER UNIT” in Chapter 3.
IGNITION SYSTEM
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