Toyota LEXUS IS 300 2003 Quick start guide

FOREWORD
Thiswiringdiagrammanualhasbeenpreparedtoprovide
informationontheelectricalsystemofthe2004IS300.
Applicablemodels:JCE10Series
Forservicespecificationsandrepairproceduresoftheabove
modelsotherthanthoselistedinthismanual,refertothe
followingmanuals;
ManualName
•2003LEXUSIS300RepairManual
Volume1
Volume2
•2003LEXUSNewCarFeatures
Pub.No.
RM1054U1
RM1054U2
NCF259U
Allinformationinthismanualisbasedonthelatestproduct
informationatthetimeofpublication.However,specifications
andproceduresaresubjecttochangewithoutnotice.
TOYOTAMOTORCORPORATION
NOTICE
Whenhandlingsupplementalrestraintsystemcomponents(removal,
installationorinspection,etc.),alwaysfollowthedirectiongivenintherepair
manualslistedabovetopreventaccidentsandsupplementalrestraint
systemmalfunction.

=2003TOYOTAMOTORCORPORATION
Allrightsreserved.Thisbookmaynotbe
reproducedorcopied,inwholeorinpart,without
thewrittenpermissionofToyotaMotor
Corporation.
1
2004IS300
ELECTRICALWIRINGDIAGRAM
INTRODUCTION.................................................A
HOWTOUSETHISMANUAL..........................B
TROUBLESHOOTING.......................................C
ABBREVIATIONS.............................................D
GLOSSARYOFTERMSANDSYMBOLS........E
RELAYLOCATIONS............................................F
ELECTRICALWIRINGROUTING....................G
SYSTEMCIRCUITS...........................................H
GROUNDPOINT..............................................I
POWERSOURCE(CurrentFlowChart).........J
CONNECTORLIST............................................K
PARTNUMBEROFCONNECTORS.................L
OVERALLELECTRICALWIRINGDIAGRAM. M
SectionCodePage

AINTRODUCTION
Thismanualconsistsofthefollowing13sections:
No.
A
B
C
D
E
F
G
H
1
J
K
L
M
Section
INDEX
INTRODUCTION
HOWTOUSETHIS
MANUAL
TROUBLE-
SHOOTING
ABBREVIATIONS
GLOSSARYOF
TERMSAND
SYMBOLS
RELAYLOCATIONS
ELECTRICAL
WIRINGROUTING
INDEX
SYSTEMCIRCUITS
GROUNDPOINT
POWERSOURCE
(CurrentFlowChart)
CONNECTORLIST
PARTNUMBEROF
CONNECTORS
OVERALL
ELECTRICAL
WIRINGDIAGRAM
Description
Indexofthecontentsofthismanual.
Briefexplanationofeachsection.
Instructionsonhowtousethismanual.
Describesthebasicinspectionproceduresforelectricalcircuits.
Definestheabbreviationsusedinthismanual.
Definesthesymbolsandfunctionsofmajorparts.
ShowspositionoftheElectronicControlUnit,Relays,RelayBlock,etc.
Thissectioniscloselyrelatedtothesystemcircuit.
DescribespositionofPartsConnectors,Splicepoints,Groundpoints,etc.
Thissectioniscloselyrelatedtothesystemcircuit.
Indexofthesystemcircuits.
Electricalcircuitsofeachsystemareshownfromthepowersupplythroughground
points.Wiringconnectionsandtheirpositionsareshownandclassifiedbycode
accordingtotheconnectionmethod.(Refertothesection,"Howtousethismanual").
The"SystemOutline"and"ServiceHints"usefulfortroubleshootingarealsocontained
inthissection.
Showsgroundpositionsofallpartsdescribedinthismanual.
Describespowerdistributionfromthepowersupplytovariouselectricalloads.
Describestheformoftheconnectorsforthepartsappearedinthisbook.
Thissectioniscloselyrelatedtothesystemcircuit.
Indicatesthepartnumberoftheconnectorsusedinthismanual.
Providescircuitdiagramsshowingthecircuitconnections.
2

HOWTOUSETHISMANUALB
Thismanualprovidesinformationontheelectricalcircuitsinstalledonvehiclesby
dividingthem intoa circuitforeachsystem.
Theactualwiringofeachsystemcircuitisshownfromthepointwherethepower
sourceisreceivedfromthebatteryasfaraseachgroundpoint.(Allcircuit
diagramsareshownwiththeswitchesintheOFFposition.)
Whentroubleshootinganyproblem,firstunderstandtheoperationofthecircuit
wheretheproblemwasdetected(seeSystemCircuitsection),thepowersource
supplyingpowertothatcircuit(seePowerSourcesection),andthegroundpoints
(seeGroundPointsection).SeetheSystemOutlinetounderstandthecircuit
operation.
Whenthecircuitoperationisunderstood,begintroubleshootingoftheproblem
circuittoisolatethecause.UseRelayLocationandElectricalWiringRouting
sectionstofindeachpart,junctionblockandwiringharnessconnectors,wiring
harnessandwiring harnessconnectors,splicepoints,andgroundpointsofeach
systemcircuit.Internalwiring foreachjunctionblockisalsoprovidedforbetter
understandingofconnectionwithina junctionblock.
Wiringrelatedtoeachsystemisindicatedineachsystemcircuitbyarrows
(from, to).Whenoverallconnectionsarerequired,seetheOverallElectrical
WiringDiagramattheendofthismanual.

*ThesystemshownhereisanEXAMPLEONLY.Itisdifferenttotheactual
circuitshownintheSYSTEMCIRCUITSSECTION.
4
BHOWTOUSETHISMANUAL

B
[A]: SystemTitle
[B]: Indicatesa RelayBlock.Noshadingisusedand
onlytheRelayBlockNo.isshowntodistinguishit
fromtheJ/B
Example:IndicatesRelayBlockNo.1
[C]: ( ) isusedtoindicatedifferentwiringand
connector,etc.whenthevehiclemodel,engine
type,orspecificationisdifferent.
[D]: Indicatesrelatedsystem.
[E]: Indicatesthewiring harnessandwiringharness
connector.Thewiringharnesswithmaleterminalis
shownwitharrows( ).
Outsidenumeralsarepinnumbers.
Thefirstletterofthecodeforeachwiring harness
andwiringharnessconnector(s)indicatesthe
component'slocation,e.g,"E"fortheEngine
Compartment,"I"fortheInstrumentPaneland
Surroundingarea,and"B"fortheBodyand
Surroundingarea.
Whenmorethanonecodehasthefirstandsecond
lettersincommon,followedbynumbers(e.g,IH1,
IH2),thisindicatesthesametype ofwiring harness
andwiringharnessconnector.
[F]: Representsa part(allpartsareshowninskyblue).
Thecodeisthesameasthecodeusedinparts
position.
[G]: JunctionBlock(ThenumberinthecircleistheJ/B
No.andtheconnectorcodeisshownbesideit).
JunctionBlocksareshadedtoclearlyseparate
themfromotherparts.
Example:
3Cindicates
thatitisinside
JunctionBlock
No.3
[H]: When2 partsbothuseoneconnectorincommon,
thepartsconnectornameusedinthewirerouting
sectionisshowninsquarebrackets[ ].
[L]
L- Y
(Blue)(Yellow)
[J]: Indicatesawiring SplicePoint(Codesare"E"forthe
EngineRoom,"I"fortheInstrumentPanel,and"B"
fortheBody).
Example:
TheLocationofsplicePointI 5 isindicatedbythe
shadedsection.
[K]: Indicatesa shieldedcable.
:Indicatesthepinnumberoftheconnector.
Thenumberingsystemisdifferentforfemaleand
maleconnectors.
Example:Numberedinorder
fromupperleftto
lowerright
Numberedinorder
fromupperrightto
lowerleft
FemaleMale
[M]: Indicatesa groundpoint.
Thefirstletterofthecodeforeachgroundpoint(s)
indicatesthecomponent'slocation,e.g,"E"forthe
EngineCompartment,"I"fortheInstrumentPanel
andSurroundingarea,and"B"fortheBodyand
Surroundingarea.
[N]: PageNo.
[I]: Indicatesthewiring color.
Wirecolorsareindicatedbyanalphabeticalcode.
B= BlackW = WhiteBR= Brown
L= BlueV = VioletSB= SkyBlue
R= RedG = GreenLG= LightGreen
p= PinkY = YellowGR=Gray
O= Orange
Thefirstletterindicatesthebasicwirecolorandthe
secondletterindicatesthecolorofthestripe.
Example:L - Y

BHOWTOUSETHISMANUAL
CurrentisappliedatalltimesthroughtheSTOPfusetoTERMINAL2 ofthestoplightSW.
When theignitionSWisturnedon,currentflowsfromtheGAUGEfusetoTERMINAL8 ofthelightfailuresensor,andalsoflows
throughtherearlightswarninglighttoTERMINAL4 ofthelightfailuresensor.
STOPLIGHTDISCONNECTIONWARNING
WhentheignitionSWisturnedonandthebrakepedalispressed(StoplightSWon),ifthestoplightcircuitisopen,thecurrent
flowingfromTERMINAL7 ofthelightfailuresensortoTERMINALS1,2 changes,sothelightfailuresensordetectsthe
disconnectionandthewarningcircuitofthelightfailuresensorisactivated.
Asa result,thecurrentflowsfromTERMINAL4 ofthelightfailuresensortoTERMINAL 11 toGROUNDandturnstherearlights
warninglighton.Bypressingthebrakepedal,thecurrentflowingtoTERMINAL8 ofthelightfailuresensorkeepsthewarning
circuitonandholdsthewarninglightonuntiltheignitionSWisturnedoff.
S6STOPLIGHTSW
2-1: Closedwiththebrakepedaldepressed
L4LIGHTFAILURESENSOR
1, 2, 7-GROUND : Approx.12voltswiththestoplightSWon
4, 8-GROUND : Approx.12voltswiththeignitionSWatONposition
11-GROUND : Alwayscontinuity
Code
C7
H17
SeePage
34
36
Code
L4
R6
SeePage
36
37
Code
R7
S6
SeePage
37
35
Code
1SeePage
18
RelayBlocks(RelayBlockLocation)
R/B No.1 (InstrumentPanelLeft)
Code
IB
3C
SeePage
20
22
JunctionBlockandWireHarness(ConnectorLocation)
InstrumentPanelWireandInstrumentPanelJ/B(LowerFinishPanel)
InstrumentPanelWireandJ/BNo.3 (Instrument PanelLeftSide)
Code
IE1
BV1
SeePage
42
50
JoiningWireHarnessandWireHarness(ConnectorLocation)
FloorWireandInstrumentPanelWire(LeftKickPanel)
LuggageRoomWireandFloorWire(LuggageCompartmentLeft)
Code
BL
BO
SeePage
50
50
GroundPointsLocation
UndertheLeftQuarterPillar
BackPanelCenter
Code
15
SeePage
44WireHarnesswithSplicePoints
CowlWire
Code
B18
SeePage
50WireHarnesswithSplicePoints
LuggageRoomWire
6
[R]
[Q]
[S]
[T]
[U]
[V]
[P]
[O]

[O]:Explainsthesystemoutline.
[P]: Indicatesvaluesorexplainsthefunctionforreferenceduringtroubleshooting.
[Q]:Indicatesthereferencepageshowingthepositiononthevehicleofthepartsinthesystemcircuit.
Example: Part"L4"(LightFailureSensor)isonpage36ofthemanual.
*Theletterinthecodeisfromthefirstletterofthepart,andthenumberindicatesitsorderinparts
startingwiththatletter.
[R]: IndicatesthereferencepageshowingthepositiononthevehicleofRelayBlockConnectorsinthesystemcircuit.
Example: Connector"1"isdescribedonpage18ofthismanualandisinstalledontheleftsideoftheinstrument
panel.
[S]: IndicatesthereferencepageshowingthepositiononthevehicleofJ/BandWireHarnessinthesystemcircuit.
Example: Connector"3C"connectstheInstrumentPanelWireandJ/BNo.3.Itisdescribedonpage22ofthis
manual,andisinstalledontheinstrumentpanelleftside.
[T]: Indicatesthereferencepagedescribingthewiring harnessandwiringharnessconnector(thefemalewiring
harnessisshownfirst,followedbythemalewiring harness).
Example: Connector"IE1"connectsthefloorwire(female)andInstrumentpanelwire(male).Itisdescribedon
page42ofthismanual,andisinstalledontheleftsidekickpanel.
[U]: Indicatesthereferencepageshowingthepositionofthegroundpointsonthevehicle.
Example: Groundpoint"BO"isdescribedonpage50ofthismanualandisinstalledonthebackpanelcenter.
[V]: Indicatesthereferencepageshowingthepositionofthesplicepointsonthevehicle.
Example: Splicepoint"l5"isontheCowlWireHarnessandisdescribedonpage44ofthismanual.

BHOWTOUSETHISMANUAL
Thegroundpointscircuitdiagramshowstheconnectionsfromallmajorpartstotherespectivegroundpoints.When
troubleshootinga faultygroundpoint,checkingthesystemcircuitswhichusea commongroundmayhelpyouidentify
theproblemgroundquickly.Therelationshipbetweengroundpoints( shownbelow)canalsobe
checkedthisway.
IGROUNDPOINT
ThesystemshownhereisanEXAMPLEONLY.ItisdifferenttotheactualcircuitshownintheSYSTEMCIRCUITSSECTION.
8

B_
The"CurrentFlowChart"section,describeswhichpartseachpowersource(fuses,fusiblelinks,andcircuitbreakers)
transmitscurrentto.InthePowerSourcecircuitdiagram,theconditions whenbatterypowerissuppliedtoeachsystem
areexplained.SinceallSystemCircuitdiagramsstartfromthepowersource,thepowersourcesystemmustbefully
understood.
JPOWERSOURCE(CurrentFlowChart)
Thechartbelowshowstheroutebywhichcurrentflows fromthebatterytoeachelectricalsource
(FusibleLink,CircuitBreaker,Fuse,etc.)andotherparts.
POWERSOURCE
ThesystemshownhereisanEXAMPLEONLY.ItisdifferenttotheactualcircuitshownintheSYSTEMCIRCUITSSECTION.
9
EngineRoomR/B(SeePage20)

BHOWTOUSETHISMANUAL
KCONNECTORLIST
[A]: Indicatesconnectortobeconnectedtoa part.(ThenumeralindicatesthepinNo.)
[B]: JunctionConnector
Indicatesa connectorwhichisconnectedtoa shortterminal.
JunctionConnector
Junctionconnectorinthismanualincludea shortterminalwhichis
connectedtoa numberofwireharnesses.Alwaysperform
inspectionwiththeshortterminalinstalled.(Wheninstallingthe
wireharnesses,theharnessescanbeconnectedtoanyposition
withintheshortterminalgrouping.Accordingly,inothervehicles,
thesamepositionintheshortterminalmaybeconnectedtoawire
harnessfroma differentpart.)
Wireharnesssharingthesameshortterminalgroupinghavethe
samecolor.
SameColorShortTerminal
[C]: PartsCode
Thefirstletterofthecodeistakenfromthefirstletterofpart,andthenumbersindicatesitsorderinpartswhich
startwiththesameletter.
[D]: ConnectorColor
Connectorsnotindicatedaremilkywhiteincolor.
10

B
LPARTNUMBEROFCONNECTORS
[A]: PartCode
[B]: PartName
[C]: PartNumber
ToyotaPartNumberareindicated.
Notalloftheabovepartnumbersoftheconnectorareestablishedforthesupply.
11

CTROUBLESHOOTING
VOLTAGECHECK
(a)Establishconditionsinwhichvoltageispresentatthecheck
point.
Example:
[A]- IgnitionSWon
[B]- IgnitionSWandSW1 on
[C]- IgnitionSW,SW1 andRelayon(SW2 off)
(b)Usingavoltmeter,connectthenegativeleadtoagoodground
pointornegativebatteryterminal,andthepositiveleadtothe
connectororcomponentterminal.
Thischeckcanbedonewithatestlightinsteadofavoltmeter.
CONTINUITYANDRESISTANCECHECK
(a)Disconnectthebatteryterminalorwiresothereisnovoltage
betweenthecheckpoints.
(b)Contactthetwoleadsofanohmmetertoeachofthecheck
points.
Ifthecircuithasdiodes,reversethetwoleadsandcheck
again.
Whencontactingthenegativeleadtothediodepositiveside
andthepositiveleadtothenegativeside,thereshouldbe
continuity.
Whencontactingthetwoleadsinreverse,thereshouldbeno
continuity.
12
(c)Usea volt/ohmmeterwithhighimpedance(10k /V
minimum)fortroubleshootingoftheelectricalcircuit.

FINDINGA SHORTCIRCUIT
(a)Removetheblownfuseanddisconnectallloadsofthefuse.
(b)Connecta testlightinplaceofthefuse.
(c)Establishconditionsinwhichthetestlightcomeson.
Example:
[A]- IgnitionSWon
[B]- IgnitionSWandSW1 on
[C]- IgnitionSW,SW1 andRelayon(Connectthe
Relay)andSW2 off(orDisconnectSW2)
(d)Disconnectandreconnecttheconnectorswhilewatchingthe
testlight.
Theshortliesbetweentheconnectorwherethetestlight
stayslitandtheconnectorwherethelightgoesout.
(e)Findtheexactlocationoftheshortbylightlyshakingthe
problemwirealongthebody.
CAUTION:
(a)DonotopenthecoverorthecaseoftheECUunless
absolutelynecessary.(Ifthe IC terminalsaretouched,
the IC maybedestroyedbystaticelectricity.)
(b)Whenreplacingtheinternalmechanism(ECUpart)of
thedigitalmeter,becarefulthatnopart of yourbodyor
clothingcomesincontactwiththeterminalsofleads
fromthe IC, etc.ofthereplacementpart(sparepart).
DISCONNECTIONOFMALEANDFEMALE
CONNECTORS
Topullaparttheconnectors, pullontheconnectoritself,not
thewireharness.
HINT:Checktoseewhatkindofconnectoryouare
disconnectingbeforepullingapart.
PullUpPullUp
PressDownPressDown
13

CTROUBLESHOOTING
Example:
(Case1)
Tool
TerminalRetainer
TerminalRetainer
[RetaineratFullLockPosition]
Terminal
StopperRetainer
[RetaineratTemporaryLockPosition]
Example:
(Case2)
Secondary
LockingDevice
HOWTOREPLACETERMINAL
(withterminalretainerorsecondarylockingdevice)
1.PREPARETHESPECIALTOOL
HINT:Toremovetheterminalfromtheconnector,please
constructandusethespecialtoolorlikeobjectshownon
theleft.
2.DISCONNECTCONNECTOR
3.DISENGAGETHESECONDARYLOCKINGDEVICEOR
TERMINALRETAINER.
(a)Lockingdevicemustbedisengagedbeforetheterminal
lockingclipcanbereleasedandtheterminalremovedfrom
theconnector.
(b)Usea specialtoolortheterminalpicktounlockthesecondary
lockingdeviceorterminalretainer.
NOTICE:
Donotremovetheterminalretainerfromconnectorbody.
[A]ForNon-WaterproofTypeConnector
HINT:Theneedleinsertionpositionvariesaccordingtothe
connector'sshape(numberofterminalsetc.), so
checkthepositionbeforeinsertingit.
"Case1"
Raisetheterminalretaineruptothetemporarylock
position.
"Case2"
Openthesecondarylockingdevice.
14

Example:
(Case1)
Tool
Tool
[Male]
AccessHole
Mark)[Female]
Retainer
atFullLockPosition
Retainer
atTemporaryLockPosition
[Male][Female]
[B]ForWaterproofTypeConnector
HINT:Terminalretainercolorisdifferent
accordingtoconnectorbody.
Example:
TerminalRetainer: ConnectorBody
BlackorWhite: Gray
BlackorWhite: DarkGray
GrayorWhite: Black
"Case1"
Typewhereterminalretainerispulled
uptothetemporarylockposition(Pull
Type).
Insertthespecialtoolintotheterminal
retaineraccesshole( Mark)andpull
theterminalretaineruptothe
temporarylockposition.
HINT:Theneedleinsertionpositionvaries
accordingtotheconnector'sshape
(Numberofterminalsetc.),socheck
thepositionbeforeinsertingit.
"Case2"
Typewhichcannotbepulledasfaras
PowerLockinsertthetoolstraightinto
theaccessholeofterminalretaineras
shown.
15
c
Terminal
Retainer
Example:
(Case2)TerminalRetainer
Tool
[Male]
PressDownPressDown
[Female]

CTROUBLESHOOTING
Retainerat
FullLockPosition
Retainerat
TemporaryLockPosition
[Male][Female]
Pushtheterminalretainerdowntothetemporarylockposition.
(c)Releasethelockinglugfromterminalandpulltheterminalout
fromrear.
4.INSTALLTERMINALTOCONNECTOR
(a)Inserttheterminal.
HINT:
1.Makesuretheterminalispositionedcorrectly.
2.Inserttheterminaluntilthelockingluglocksfirmly.
3.Inserttheterminalwithterminalretainerinthetemporarylock
position.
(b)Pushthesecondarylockingdeviceorterminalretainerinto
thefulllockposition.
5.CONNECTCONNECTOR
16

ABBREVIATIONSD
ABBREVIATIONS
Thefollowingabbreviationsareusedinthismanual.
A/C
A/T
ABS
ACIS
BA
COMB.=
ECU
ESA
ETCS-i=
EVAP
FFC
IC
J/B
LCD
LED
LH
MPX
O/D
R/B
RH
S/D
SFI
SRS
SW
TEMP.=
TRAC=
VSC
VSV
W/G
w/
w/o
AirConditioning
AutomaticTransmission
Anti-LockBrakeSystem
AcousticControlInductionSystem
BrakeAssist
Combination
ElectronicControlUnit
ElectronicSparkAdvance
ElectronicThrottleControlSystem-intelligent
EvaporativeEmission
FlexibleFlatCircuit
IntegratedCircuit
JunctionBlock
LiquidCrystalDisplay
LightEmittingDiode
Left-Hand
Multiplex
Overdrive
RelayBlock
Right-Hand
SedanType
SequentialMultiportFuelInjection
SupplementalRestraintSystem
Switch
Temperature
TractionControl
VehicleStabilityControl
VacuumSwitchingValve
WagonType
With
Without
*Thetitlesgiveninsidethecomponentsarethenamesoftheterminals(terminalcodes)andarenottreatedasbeing
abbreviations.
17

EGLOSSARYOFTERMSANDSYMBOLS
BATTERY
Storeschemicalenergyand
convertsitintoelectricalenergy.
ProvidesDCcurrentfortheauto's
variouselectricalcircuits.
GROUND
Thepointatwhichwiringattachesto
theBody,therebyprovidinga return
pathforanelectricalcircuit;withouta
ground,currentcannotflow.
CAPACITOR(Condenser)
Asmallholdingunitfortemporary
storageofelectricalvoltage.
CIGARETTELIGHTER
Anelectricresistanceheating
element.
HEADLIGHTS
1.SINGLECurrentflowcausesa headlight
FILAMENTfilamenttoheatupandemitlight.A
headlightmayhaveeithera single
(1)filamentora double(2)filament
2.DOUBLE
FILAMENT
CIRCUITBREAKER
Basicallya reusablefuse,a circuit
breakerwillheatandopeniftoo
muchcurrentflows throughit.
Someunitsautomaticallyresetwhen
cool,othersmustbemanuallyreset.
HORN
Anelectricdevicewhichsoundsa
loudaudiblesignal.
DIODE
Asemiconductorwhichallows
currentflowinonlyonedirection.
IGNITIONCOIL
Convertslow-voltageDCcurrent
intohigh-voltageignitioncurrentfor
firingthesparkplugs.
DIODE,ZENER
Adiodewhichallowscurrentflowinone
directionbutblocksreverseflowonlyup
toa specificvoltage.Abovethatpotential,
itpassestheexcessvoltage.Thisactsas
asimplevoltageregulator.
LIGHT
Currentflowthrougha filament
causesthefilamenttoheatupand
emitlight.
PHOTODIODE
Thephotodiodeisa semiconductor
whichcontrolsthecurrentflow
accordingtotheamountoflight.
LED(LIGHTEMITTINGDIODE)
Uponcurrentflow,thesediodesemit
lightwithoutproducingtheheatofa
comparablelight.
DISTRIBUTOR,IIA
Channelshigh-voltagecurrentfrom
theignitioncoiltotheindividual
sparkplugs.
METER,ANALOG
Currentflowactivatesa magnetic
coilwhichcausesa needletomove,
therebyprovidinga relativedisplay
againsta backgroundcalibration.
FUSE
Athinmetalstripwhichbumsthrough
whentoomuchcurrentflowsthroughit,
therebystoppingcurrentflowand
protectinga circuitfromdamage.
FUSIBLELINK
(forMediumCurrentFuse)A heavy-gaugewireplacedinhigh
amperagecircuitswhichburnsthroughon
overloads,therebyprotectingthecircuit.
Thenumbersindicatethecrosssection
surfaceareaofthewires.
METER,DIGITAL
Currentflowactivatesoneormany
LED's,LCD's,orfluorescent
displays,whichprovidea relativeor
digitaldisplay.
(forHighCurrentFuseor
FusibleLink)
MOTOR
Apowerunitwhichconverts
electricalenergyintomechanical
energy,especiallyrotarymotion.
18

Basically,anelectricallyoperated
switchwhichmaybenormally
closed(1)oropen(2).
Currentflowthrougha smallcoil
createsa magneticfieldwhicheither
opensorclosesanattachedswitch.
RELAY,DOUBLETHROW
Arelaywhichpassescurrent
throughonesetofcontactsorthe
other.
SPEAKER
Anelectromechanicaldevicewhich
createssoundwavesfromcurrent
flow.
SWITCH,MANUAL
1.NORMALLY
OPEN
2.NORMALLY
CLOSED
Opensandcloses
circuits,thereby
stopping(1)or
allowing(2)current
flow.
RESISTOR
Anelectricalcomponentwitha fixed
resistance,placedina circuitto
reducevoltagetoa specificvalue.
SWITCH,DOUBLETHROW
Aswitchwhichcontinuouslypasses
currentthroughonesetofcontacts
ortheother.
RESISTOR,TAPPED
Aresistorwhichsuppliestwoor
moredifferentnonadjustable
resistancevalues.
RESISTOR,VARIABLEorRHEOSTAT
Acontrollableresistorwitha variable
rateofresistance.
Alsocalleda potentiometeror
rheostat.
SWITCH,IGNITION
Akeyoperatedswitchwithseveral
positionswhichallowsvarious
circuits,particularlytheprimary
ignitioncircuit,tobecome
operational.
SENSOR(Thermistor)
Aresistorwhichvariesitsresistance
withtemperature.
SWITCH,WIPERPARK
Automaticallyreturnswiperstothe
stoppositionwhenthewiperswitch
isturnedoff.
(ReedSwitchType)
SENSOR,SPEED
Usesmagneticimpulsestoopen
andclosea switchtocreatea signal
foractivationofothercomponents.
TRANSISTOR
Asolidstatedevicetypicallyusedas
anelectronicrelay;stopsorpasses
currentdependingonthevoltage
appliedat"base".
SHORTPIN
Usedtoprovideanunbroken
connectionwithina junctionblock.
SOLENOID
Anelectromagneticcoilwhichforms
amagneticfieldwhencurrentflows,
tomovea plunger,etc.
WIRES
Wiresarealwaysdrawnas
(1)NOTstraightlinesonwiring
CONNECTEDdiagrams.
Crossedwires(1)withouta
blackdotatthejunctionare
notjoined;
crossedwires(2)witha
(2)SPLICEDblackdotoroctagonal(O)
markatthejunctionare
spliced(joined)
connections.
19
E
RELAY
1.NORMALLY
CLOSED
2.NORMALLY
OPEN