alternator LEXUS SC300 1991 Service Manual PDF
[x] Cancel search | Manufacturer: LEXUS, Model Year: 1991, Model line: SC300, Model: LEXUS SC300 1991Pages: 4087, PDF Size: 75.75 MB
Page 3868 of 4087

26
ELECTRICAL WIRING ROUTING
Position of Parts in Engine Compartment
A 1 A/C Ambient Temp. Sensor E 1 ECT Solenoid
A 2 A/C Lock Sensor and A/C Magnetic Clutch E 2 EFI Water Temp. Sensor
A 3 A/C High Pressure SW E 3 EGR Gas Temp. Sensor (for USA Spec.)
A 4 ABS Actuator E 5 Engine Hood Courtesy SW
A 5 ABS Actuator (w/ Traction Control) E 6 Engine Oil Level Warning SW
A 6 ABS Actuator (w/ Traction Control)
A 7 ABS Speed Sensor Front LH F 1 Front Airbag Sensor LH
A 8 ABS Speed Sensor Front RH F 2 Front Airbag Sensor RH
A 9 Air Flow Meter F 3 Front Clearance Light LH
A 10 Alternator F 4 Front Clearance Light RH
A 11 Alternator F 5Front Side Marker Light LH
A 33 ABS Actuator (w/o Traction Control) F 6 Front Side Marker Light RH F 7 Front Turn Signal Light LH
B 1 Brake Fluid Level SW F 8 Front Turn Signal Light RH
B 6 Back±Up Light SW (for M/T) F 9 Fuse Block
C 3 Check Connector H 1 Headlight Hi LH
C 6 Cornering Light LH H 2 Headlight Hi RH
C 7 Cornering Light RH H 3 Headlight Lo LH
C 8 Cruise Control Actuator H 4 Headlight Lo RH H 5 Horn LH
D 13 Distributor H 6 Horn RH
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Page 3953 of 4087

OVERALL ELECTRICAL WIRING DIAGRAM
1234
1 LEXUS SC300 (
Cont . ne xt pa ge )
2 1
5
3
1J
7 1J
31J 5
3D
1
1B
4 1E
81H 52 2
3D
2
16 IE1
1EB2 15 IE1 3EB1
2
5IJ2 13IJ2 2EB2
1A B B
B
B
L
IG
S 1J
6
1K
4
1
C
1
D
4
ACC
IG1
ST1
IG2
AM1 2
1
6
11 AM2
15 14 2
2
2
1IG3
W
W± R B±Y
B±W
B± O
Y± G
B±YW
B
W± L
W
W± R
W± R
B
W
B±Y W
B
B B
B± W L±O
B B±O
B
B±W
Y± G
Y±G
Y±G
B± Y
W
B
B L±O
Y±G
B
W± R
4 7 9 14 13 5
6
120A ALT
100A AM1 30A I NJ
30A AM2
60A MAIN
F9
FUSE BL OCK
40A I GSW
I15
IGNITION SW
C12
CHARGE WARNING
LIGHT 7. 5A
ENGINE
7. 5A
AL T
SENCI NG
To Integr ation
Relay< 5±4> STARTER
RELAY
7. 5A
ST
N1
NEUTRAL
START SW
To Theft Deterrent
and Door Lock ECU
< 18±3>
To Engine and
ECT ECU< 2±2>
STARTER
AL TERNATOR
BATTERY
2
3
1
Charging Starting
B± O
Y± G
3
4
S6 D , S7 C
(Canada )
12
11
6IJ1
A1 0 B , A11 A 1
23 1
BA
A1 0 A11 BL ACKALTERNATOR 1
1
D
C
START ER
S6
S7 BROWN
Power Source
Y± G
2 1
IJ2 8B B
B± WB±W
(A/ T )
(
A/T )
(M/T )
(
M/T )
B C2 3
CL UTCH
START SW
B
2
3
P
N
B±O
B±O
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Page 3961 of 4087

OVERALL ELECTRICAL WIRING DIAGRAM
1234
5 LEXUS SC300
1J
7 22 2 21J
81B2
4
1B
5
1B
4 1K
11
22 22
22
44
1I 1E
3 1
4 2 3
4
1 2 23
1
5
4
ACC
IG1
ST1
AM1 3
2
1 21 2 1
21
2
19 IE1 12 IE1 11 IE1 5IE1 6IE1
9IG1
4
7
6 4
15 19 21 1
3 16 20 22 2
18 497 313
6 7
IJ 8IG1 1J
5
3A 1E 1C
1A
1I
15
1C
1F
1K 3D
7B 1A
2 1 9
10
BK IF 1H
1K 1J 1E W± BY Y
G± O G
G
W± L
Y
Y
W±B
R
W±B W±B R±YW± G
G± W
W± LW± L
W± L W
W± B
R±W W± B
W± B
R
R
LG±B G±W
L±W P± B
G±L
R± W
R± W
BR± W
B±L
B± L
W± B
W± B
W±B W±B W±B W±B W±B
W± B W± B
R±W
R±W
R
W±B R±B R± W
R± W R±G
R
W
G± W
G± W R
R R
W
P±L W
G G
P±L
B±Y
W
R± Y R±L R
Y VPower
Source
F9
FUSE BL OCK60A MAIN
100A AM1
120A ALT
22W
R±Y
TH
15A
HEAD
LH±LWR
15A HEAD RH±LWR
15A HEAD RH±UPR 15 A HEA D L H± UP R
40A
IGSW
H3LH
H4 RH
H2 RH H1LH
HEADLIGHT
(
LO )
HEADLIGHT (
HI )
DIMMER
RE LA Y HEADLIGHT
RELAY
Fr om Connerring Light
Relay< 8±7> DI ODE10A DOME
7. 5A RADIO No. 2
LIGHT
CONTROL
DIMMER
OFF
TAI L
HE AD
LOW
HI GH
FLASH ED HL HU HF EL T H
C15
COMBINATI ON
SW
BATTERY
C13
HIGH BEAM
I NDI CA TOR L I GHT
[COMB. METER]
To Door Lock Mot or and
Unlock Detection SW and
Doo r Open De t ect i on S W LH
< 17±1>
To Door Lock Mot or and
Unlock Detection SW and
Doo r Open De t ect i on S W RH
< 17±1> From Open Door War ning Light
From Per sonal Light< 6±2>
B4
BACKLE SW LH
I15
UNLOCK WARNING SW
[IGNITION SW] SEAT BELT WARNI NG
LI GHT[ COMB. MET ER]
5118
TAIL LIGHT
RELAY
To Thef t
Deter rent and
Do or L oc k ECU
< 17±3>
7. 5A PANEL15A TAIL
10A
GAUGE
3 12 2
13 4Y
BELT
H± LP B A CC TA I L I NTB I G
BKL KEY
12 2
9
To Thef t Deter rent
and Door Loc k ECU
< 17±3>
I15
IGNITION SW
I16
I NTEGRAT I ON REL AY
DIM TOUT
HF
HU
Y± B
R±L
CHG± P KBY±G
B
From Alternator º Lº < 1±2>
From Park ing Br ake SW < 21±2>
1 3 2
B±Y
G± O
1C
16DI ODE
1E
1
9
C1 2 , C1 4 AB
6
From Tens ion Reducer
Solenoid LH< 11±7>
Fr om Thef t Deter rent and
Door Loc k ECU< 17±2>
Fr om Day /Night Shift SW< 12±1>
Fr om Tilt and Power Teles copic
ECU< 11±1> Y
Y
W±B
12C 11C 5C
CCC CC 4C2C 9 8 7 10 13 111 12 7
642 8 105 GND
I NTEGRATI ON REL AY
SEAT BELT
WARNING LIGHT
[COMB. METER]
10 11 12 13 17 18 19 20 21 12345 6789
14 15 16
17 18
1 2345 6789 10
23
22
21
20
19
15
14
13
12
11 16 C
A
B I16
C12
C1 4
Headlight (
for Canada ) Unlock and
Seat Belt Warning
(
for Canada )
(
Cont . ne xt pa ge )
2
1
3C 1C
13
Y
12345678910111213
18
17
IG
W±B
6Ba2Ba 1
11
5Ba2 Ba 1
12 (
w/ Memor y )
( w/o Memory )
B±L
( w/ Memor y )
( w/o Memory )
XX
Right kic k panel
Unlock the center
pillar LHLeft kic k
panel
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Page 3965 of 4087

OVERALL ELECTRICAL WIRING DIAGRAM
1234
8 LEXUS SC300 (
Cont . ne xt pa ge )
4 ACC
IG1
ST1
AM1 2
1J
7 66 66 66 66
21J
5
1B
4 6666
66 66 66 2 1I
8
4 3 5 4
2
4 3
2
1 4
3
2
1 6
4
3
1
71124 1F 2F 3F
AABA A A B
C
B
A
B
A
A
A
A
A
A
BAABAABBB A A A A A B GGGF F
F
M
15 2 12 1 25 21 24 10 1 9
1 1326128 7 222 13 5 18 16 17 4 4 7IE2
1IO1
2 3
1 2
1
6
EB EA IJ M
2Bc2
12 IE2
H
4H 5H6H1H 2H3
I
2I 1J1
SFR SFL SRR SRL AST MT BSR BSM BSA
BS BM GND E2 PR VC SRC SMC SAC
MTT
BT M
EM2
BBBBBBBC
C
C
C
C
C
C
C
C
C
C
B
B
C 9IO1
EB1
6
10 IO1
3BW1 8BW1
6Bc2 5Bc2 2BW1 6BW1
7BW1
3B
1
221 1 112 2 320 741361511 7 81214 510
15 5 14 3 8 6 17
SFR SFL SRR SRL AST MT GND1 GND2 GND3 FL+ FL± FSS FR+ FR± RL+ RL± RSS RR+ RR± ALT LVL1 PKB W
B± Y
B±R
B±R R
VL
P± B
V±W R±B P
Y± B
LG
LG±B P± L
P± G
V±R
L
GR B
R± W
W±B (
SHIELDED )(
SHI ELDED)
B± R B± R
W± B L± Y G
V±Y
R± W
W± B MTT SR MR TMR E2 PR VC SRC SMC SAC TSR R± BAT I G STPTS WA TC D/G ABSO
RLORRO
FL OFRO
BRFA THFA
BRCBRP
TRCO NL PW±LR
Y
W
W
L±W B±R
R±B
L
Y R
V±Y
V±Y
V±Y
W
B±Y
R
R±W R
B±R
B±R
R
G± W
G±W B±Y
L±Y
R± B
Y
G
( SHI ELDED )
W
B
R
V± Y
V
V± W R± W R±W R±W
B±R V±Y W
W± L
V L
P±B
W± B W± B W± B
L±W Y± G
P± B P
B± Y
Y
L±W
L
W± B
W± B W± B
W
B
O±L
W± L W
O
O
W
W
O
L±GL±Y
L±G
L±Y Y±G Y±G
B
R±W
LR±W
B±Y V±R P± GP± L
LG±B LG
Y±B
P
R± B R±B V± W B±R B±R
V± Y
W±B W±B
(SHIELDED )
(
SHI EL DED )
(
SHI ELDED )I15
IGNITION SW
40A
IGSW
4 2 1456
R
T5
TRACTION PUMP
A N D MOT ORTRACTI ON BRAKE
ACTUATOR
ABS AND T RACTI ON ECU
60A MAIN
30A ABS NO. 2 60A ABS
NO. 1100A AM1
ABS
ACTUATOR
RELAY
ABS MOTOR
RELAY
TRACTION MOTOR
RELAY
TRACTION BRAKE
MAI N RELAY
10A DOME
6 BATTERY AB S A CT UA TOR
(SHI ELDED ) W± B
A7
ABS SPEED SENSOR
FRONT LH
A8
ABS SPEED SENSOR
FRONT RHA30
ABS SPEED SENSOR
REAR LH
F9
FUSE BLOCK
B±Y
From Stop Light
SW<4±6><5±6>
5BW1
A31
ABS SPEED SENSOR
REAR RH
From Alternator
º Lº < 1±2>
Power
Source ABS and Traction Control
B±R15A ECU±IGY
23 22 16 9 20 10 19
T3 ,T4
FG
(
SHI ELDED )
A4 , A5 , A6
HJ I A2 4 A , A25 B , A2 6 C
W
120A ALT
R
Fro nt s id e of
left fenderRight kick panel
Fr ont side of
right f ender
1
3
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Page 3991 of 4087

44
POWER SOURCE (Current Flow Chart)
The chart below shows the route by which current flows from the battery to \
each electrical source
(Fusible Link, Circuit Breaker, Fuse, etc.) and other parts.
The next page and following pages show the parts to which each electrica\
l source outputs current.
Taillight
Relay (Point Side)
30A AM260A MAIN 50A DEFOG
60A HEATER
7.5 TRAC
40A IG SW
120A ALT
Starter Relay
(Point Side)
Headlight Relay
(Point Side)
30A EFI
15A TEL
10A DOME
20A RADIO No. 1
25A HAZ±HORN
Theft Deterrent and
Door Lock ECU
15A HEAD RH
(USA) 15A HEAD LH
(USA)
Dimmer Relay
(Coil Side)
Starter
15A STOPIgnition SW
(AM1)
30A DOOR
15A TAIL
Alternator
ABS Motor Relay
(Point Side)
Defogger
Relay
Starter ABS
Actuator
10A MIR±HTR
15A ECU±B 7.5A PANEL
7.5 IGN
Engine ECU Traction Brake
Actuator
30A INJ
60A ABS No.1
Traction Brake
Main Relay
(Point Side)
ABS
Actuator Relay
30A POWER
Integration
Relay
100A AM1
Seat Heater
Relay (Point Side)
7.5 ALT SENCING
30A ABS No.2 Headlight
Relay
(Coil Side)
Traction Motor
Relay (Point Side)Traction Pump
and Motor Dimmer Relay
(Point Side) Ignition SW
(AM2)
Taillight
Relay (Coil Side)
15A HEAD (LH±LWR)
(CANADA)
15A HEAD (RH±LWR)
(CANADA)
Engine and
ECT ECU
15A HEAD (LH±UPR)
(CANADA)
15A HEAD (RH±UPR)
(CANADA) ABS and
Traction ECU
Battery
[LOCATION](1): J/B No. 1 (See page
20)(2): R/B No. 2 (See page 19)(3): R/B No. 4 (See page 23)
20
19 22
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Page 3993 of 4087

46
POWER SOURCE (Current Flow Chart)*1: USA
*2: CANADA
60
216
226
192178
226 90 144 134 216 102 202
208
212 90
167
A2 A15 C6 B2
B1
A10 A14 A12 A17A13 A23 A24 A25 A32 C11 B3 B4 B6 C3 C10C7
A21
Blower Resistor Auto Antenna Motor
And Relay A/C Magnetic Clutch
Alternator
A/C Control Assembly
A/C Power Transistor
A/T Indicator Light
(for Shift Lever) A/C Control SW and
Radio SWABS ECU
ABS and Traction ECUBrake Fluid Level SW
Blower Motor
Center Airbag Assembly Check Connector
Cornering Light LH
Cigarette Lighter Back±Up Light SW Buckle SW LHABS and Traction ECUCornering Light RH
190
226 22690
126
226 10168
134
144
178
* These are the page numbers of the first page on which the related system\
is shown.
The part indicated is located somewhere in the system, not necessarily o\
n the page indicated here. *Page Nos. of
Related Systems
Parts
Code or
Location
CB or Fuse
50A DEFOG
30A DOOR
30A POWER
15A STOP
15A ECU±B
10A MIR±HTR
10A HEATER
20A TURN
20A WIPER
10A GAUGE
15A ECU±IG
7.5A ENGINE
7.5A IGN
15A CIG
7.5A RADIO No.2
15A TAIL
7.5A PANEL
7.5A ST
15A TEL
10A DOME
20A RADIO No.1
25A HAZ±HORN
30A EFI
7.5 ALT SENCING
15A HEAD LH*1
15A HEAD RH*1
15A HEAD LH±LWR*2
15A HEAD RH±LWR*2
15A HEAD LH±UPR
15A HEAD RH±UPR
60A HEATER
7.5A TRAC
15A SEAT±HTR
Location
[LOCATION](1): J/B No. 1 (See page 20)(2): R/B No. 2 (See page 19)(3): R/B No. 4 (See page 23)
20
19 22
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Page 4001 of 4087

56
POWER SOURCE
AM2 AM1
ACC
IG 1
IG 2
321 6 411
ST1
1B
2
1J 5
1J 6
1J 3
1J 8 1K
13
1K 4
1J
4
1B
4
1J
7 I24
I33
I11 P
N 2
3
IE1
16
IJ16
3421314 59 7
116
W
WB
B
B
B±R
B±W B±W
W±L
B
B±O P±L B
B
B
W±L R
W±R
W±R
B
W±R Y
W±L
W±R
W
W±R
B±Y
B±W P±L
B±O
B±W
B±W
B±W
B±WW
B±R
15A ECU±B
15A STOP
30A POWER
30A DOOR
TAILLIGHT
RELAY 15A TAIL
7. 5A PANEL BATTERY
15A ECU±IG
7. 5A ENGINE
20A W IPER
10A GAUGE 20A TURN
10A HEATER
7. 5A ST
7. 5A IGN 15A CIG
7. 5A RADIO NO. 2
40A
IGSW
NEUTRAL
START SW
TO ENGINE AND ECT ECUTO CRUISE CONTROL ECU
TO ABS ACTUATOR RELAY,
ABS MOTOR RELAY AND
TRACTION BRAKE
ACTUATOR RELAYTO ALTERNATOR º Bº
IGNITION SW
FUSE BLOCK
TO TRACTION MOTOR RELAY100A AM1
60A ABS NO. 1
30A INJ
120A ALT 30A AM2
30A ABS NO. 2 60A MAIN
F9
N1
I15
5
1 3
2
2
6
3 4 1
5
1 2IJ2
8 B
B±W
B
B
(
M/T )
(
M/T )
C23
CLUTCH START SW
(
A/T )
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