1991 LEXUS SC300 alternator

SERVICE SPECIFICATIONS
SERVICE DATA
BatterySpecific gravity1.27±1.29
(when fully charged at 205C (68 5F))
AlternatorRated output12 V±100 A
Rotor coil resistance2.8±3.0

Slip ring diameterSTD 14.2±14.4 mm0.559±0567 in.
Limit 12.8 mm0.504 in.
Brush exposed lengthSTD 10.5 mm0.413 in.
Limit 1.5 mm0.059 in.
AlternatorRegulating voltageat 255C (77 5F)13.9±15.1 V
regulatorat 115 5C (239 5F)13.5±14.3 V
TORQUE SPECIFICATIONS
Part tightenedN Vmkgf Vcmft Vlbf
Alternator pulley X Rotor11 01,12581
Alternator X Alternator bracket37380 27
Alternator X Cylinder block3738027
±
CHARGING SYSTEM Service SpecificationsCH±21
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135
B
4 RL+
B
15 RL±
B
5 RSS
B
14 RR+
B
3 ALT
BW1
3BW1 8
BW1
2
BW1
5
BW1
6
Bc2
6
Bc2
2 I26
12 12
W O W±B
L±G
L±Y
W
O
L±G L±Y
W
O
L±G L±Y
(
SHIELDED ) (
SHIELDED )
(
SHIELDED )
REAR LH REAR RH A3 1
A3 0
ABS SPEED SENSOR
M
6
1
4
36
6
66
TRACTION BRAKE
MAIN RELAY
2 16 22
3
1 23 11
E7
I25 I32
I23
EB1
6
IO1
7 IK2
2
A
23
MTT A
1
TSR A
20
E2 A
19
VC A
10
PR A
15
SRC A
2
SMC A
12
SAC C
1
TS B
9
WA C
3
TC
A
1A 2A3
A
4A 5A6
B
2
B
1 B
4
L±Y
B±R
L
L
L
L VB±R
P±B
P±B B±R
R±W
R±W
R±W
W
R
B
V±Y V
V±W B±R
R
R±W
V±Y
TS WA
R
B±R
L±Y
W±B V±Y
W±B W±B P±B
L
TC
WB
T5 T3
,
T4C3
TRACTION PUMP
AND MOTOR TRACTI ON BRA KE
ACTUATOR
CHECK
CONNECTOR
BA
(
SHIELDED )
C
ABS AND TRACTION ECU A24 ,
A25 ,A26
AB P±B
P±B
ACC CUT MIC CUT
RESERVOIR
CUT
(
SHIELDED )
A
17 FR+
A
4 FR±
A
16 FS S
I26
21(
SHIELDED )
O±L
W±L W±B
W±L O±L
A8
FRONT RH B
8
IO1
10
3B
1
3B
2
IJ 1
5 IG3
1
A1 0
ALTERNATOR Y±G
Y±G
Y±G
Y±G
Y±G
RR±
I26
B17
BR
BR
I26
B34
BW1
7
Bc2
5 B17
B36
BR±B BR±B BR±B
BR±B
(
SHIELDED )
2
SHORT
PIN
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60
CHARGING
1E
81H 52
3D
2 2
3D
1
IG3
1 IJ2
13 EB2 2
IJ1
5
A
A
A
231
LIG S B 1B
IC REGULATOR
6
11
57 1412
15
WB W B
W
B±O
Y±G
Y±G
Y±G
Y±G
Y±G B±Y W
B B±Y
W B±Y
W
B
FUSE B LOCK
BATTERY 7. 5A
IGN
7. 5A
ENGINE 7. 5A
ALT
SENCING
CHARGE W ARNING
LIG HT
[COMB . METER]
120A ALT
60A MAIN
A1 0 ,A11
A
B
ALTERNATOR
F9
C12
FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
Y±G
TO INTE GRATION
RELAY
( CANADA )
I14
Y±G
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61
A10(A) ALTERNATOR
(A) 1±GROUND : 13.9±15.1 VOLTS WITH ENGINE RUNNING AT 2000 RPM AND 25°C ( 77°F)
13.5±14.3 VOLTS WITH ENGINE RUNNING AT 5000 RPM AND 11 5°C ( 239 °F)
(A) 2±GROUND : 0±4 VOLTS WITH IGNITION SW AT ON POSITION AND ENGINE NOT RUNNING
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
A10A26C1228
A11B26F 926
: RELAY BLOCKS
CODESEE PAGERELAY BLOCKS (RELAY BLOCK LOCATION)
219ENGINE COMPARTMENT LEFT
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CODESEE PAGEJUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)
1E20INSTRUMENT PANEL WIRE
1H20COWL WIRE
3D22INSTRUMENT PANEL WIRE
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
EB234ENGINE WIRE AND ENGINE ROOM MAIN WIRE (FRONT SIDE OF R/B NO 2)EB234ENGINE WIRE AND ENGINE ROOM MAIN WIRE (FRONT SIDE OF R/B NO.2)
IG338INSTRUMENT PANEL WIRE AND COWL WIRE (RIGHT KICK PANEL)
IJ136ENGINE WIRE AND COWL WIRE (RIGHT KICK PANEL)IJ236ENGINE WIRE AND COWL WIRE (RIGHT KICK PANEL)
: SPLICE POINTS
CODESEE PAGEWIRE HARNESS WITH SPLICE POINTSCODESEE PAGEWIRE HARNESS WITH SPLICE POINTS
I1438COWL WIRE
X X
14 15 6 5
7
1
23 1
B
A
A10 A11 C12 F 9 BLACK BLACK
SERVICE HINTS
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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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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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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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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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