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fault-traci wage
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Contents 3
Contents
INGODUSHON: carccaiey tcaatece eatie heme Pee eee 4 Lighting systems
Safety instructions: «2.2 sss oos a Nig OU Ud keane erie nin Meat Deka Meme er 414
Wiring diagrams eT fase tw 4 PGK ie ete Or cco naveeielten ab aieeaeaar “3 358
Gab SGI. ~coasn nna awtrnonthierstae Tet 5 Dim dipped beam GB. .....6. seen esas scans eee 122
Abbreviations .... ae 5 Grake lights: occ iis sso seeee hasas vara coat 126
Using the wiring diagram: ERMAN ak 6 REVOPSINS HENS 5-5 cera ewes aed ode bees 130
Using a universal instrument for fault- ‘tracing. 8 sgl AN deh ae ORS Rg Bere miele on aos
Connectors . s honths is oa tea, setae Direction indicators, hazard warning lights, SE, Fl,
, € EUS GR ME CRP AUy saosisteinenbenchareasl sale eaearsicee 138
Power Supply Direction indicators. hazard warning lights,
Positive supply ,,...-... Were eae eee eres 572 MSP ORE Woes rd cue a tate wla nn Mnkred ume ects 142
Electrica! distribution box Uitaeasst Mimeetncr CEA Sieh ese Lighting for controls. SE, Fl, EU, GB, ME, FE, AU... 146
POG UNCAiiGcn OO eee 13 Lighting for controls US, CA, JP .... 0... c. ccc coe, 150
FUROR...» vnnmeretcnitens aeath ae Interior lighting ii... iat abavelus Hala area ies 154
WV Lambda relay box ...,.... ee Fr Interior lighting Convertible i... cy cee eee res 158
ie ignition switch and positive stinbib Sree Glove compartment illumination OAR CST TIANG u,.95Es 162
Luggage compartment illumination ..,.........+- 166
Distribution terminal +30 (1988) ............. 18 Extra fog LAMPS 0... cece cree yee eet epuveevenues 170
Distribution terminal +X -..,2,....0.0.....-.. 20
Distribution terminal +15 2. 2...2-.;cc0cvcuve = 22 Windscreen and headiamp wipers
Distripution terminal +54 .....5. 2.2. .2.2 222) 24 Windscreen WIPES... <1... eens nese sig cers 174
CAH GMWBREADE 2 3.55161 chemin enassicnslisis 7 Headlamp wipers .............-.0-- See eee 178
General ........22.. ap WER CMR erage ont, we Instruments and warning systems
ERTIES BONIS 5, get oceceeevecceso pier eitjecscaseaverece » see PROM esacec matseratce sabe eae Geant Naeeecatsaes rest oe
EACAE HONG viccsnyacoseeoreuje cnwiaesesaue Oe Seat-belt warning lamp, SE, Fl, EU, GB, ME, FE, AU 9186
Barthint DOINCD S .casercsacwwetcceees: 8689 Seat-belt and ignition key warning, US, CA, JP ..,. 196
Earthing point 65. <2 2220220)... ce ke. 34 Combined instruMent ...... 6c. e ese ece esse ene 194
Earthing point 93 ..........,........ Gast Ch Coolant temperature waming buzzer ....-........ 204
Cigarette lighter .....,...... Viveriesen vetadie ts 208
EMAAR tice ccc oe tease cele etuamnes ozs 36 Shift-up indicator 912
Negative distribution terminal CSR sxe aceee G8 Dem aren gr mek ee nara. wale Ne
Earhine point 2OL oh ised ered... 80 Heating and ventilation systems
Cooling: system fan. a: ss. bacaaice) dees eens 216
Lo Engine electronics Venti’ ie a coscpusccws ecueeononenewcnecioen 220
Starting system oe ee reer ee eee 42 Air Conditioner (AC) with time-delay relay ....,.,.. 224
Fuel system, carburetor engine o-oo, 46 Electrically heated front seats ......,.......,...- 230
Cl fuel system 18, 78, SE, Fi, EU, GB, ME, FE ...... 50 Electrically heated front seats with rheostat contro!
Cl fuel system; 18 Lambda 1987 model, SE,EU .,. 54 for the driver's seat ............................ 234
a ses ety steht ae Hit beh bee = Electric heating for the rear window .,.,,......... 238
or) Cl fuel system: T8lambde 1988 model. SE-EU |. 60 Electric heating for the rear window, Convertible 242
C| fuel system: 18 Lambda 1987 model, US, CA, Other systems
SRRAL. o_o, ee eerie dem areseerns | reer yen 64 Electric window regulators .......-.,.2.--.e,400. 246
Cl fuel system: I8 Lambda 1988 model, US, CA, Electric window regulators, Convertible ......,.... 250
JPAU 2.0. eeu 966 Electrically operated rear-view mirrors ....,-.,..-. 254
- ) LH fuel system 2. 2: \16 SE. Fl. ‘EU, GB. ei) Electrically operated sunroof ,........,...-.00.05 258
' LH fuel system 2.2: 116 Lambda, 1987, US, CA, JP. Electrically operated Convertible top -..........., 262
SE, EU, AU . : vasa: Te CONTA IOCKIE. ees owes eats esttee tuiswawesnee 266
LH fuel system 2. 2: 16 SE, Fi, EU, GB, ME, FE. a: | PS Central locking, Convertible ........)..-.0-0..05 270
LH fuel system 2.2: T16 Lambda, US, CA, JP. SE, Speed Control system .......52 200s y eee eevee 274
ER AUF ecco: aaiarerinsinens weorip ete ee arr seat r aes 78 Passive seat belts. is. censuses ies civeeeees 278
LH fuel system 2,4: 116 Lambda, 1988, US, CA, JP, Accessories
RE et LEONEAN seesaesee MG ARGUMIAHOD gos cccssyuita cea Neunareeens cts 284
Ignition system with tachometer and timing service Radio installation, 1988 (US) .....,.....-....... 286
Sette SOChet— T9675 chistes ' i. “90 Burglar alaveh:<csccccco2coccsccuceae antes 290
gnition system with tachometer and timing service F
instrument socket—1988 2.02)... . clea cee, 92 nak eahaiata ‘uambiasimiibiabtnieg SS 294
EZK ignition system with tachometer and timing List of components
service instrument socket — 1987 .........6...-. 96 Components in numerical order ..;.......,,.0005 298
EZK ignition system with tachometer and Liming Components in alphabetical order .....,......... 301
service instrument socket- 1988 ...........,,., 100
Battery-charging system ..... USA sasehd/euy aleve fees ovs.e 106
APC-system ........ Was aids steessy 205 eles arp yy ne gpmse-p 110
Saab 900
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Introduction 5
Cable code
As a general rule, each cable in the electrical system
of the car has a code consisting of three parts, as
illustrated by the example below:
1224 GN 0.75
\tem number =}
Colour code
Cross-sectional area of the conductor, mm?
Item number. Every cable is designated by a unique
number, which is usually followed by a letter desig-
nation, Cables designated with the same number,
e.g, 122, 122A, 1228, etc, usually belong to the
same sub-system.
Colour code. The following colour codes are used in
the wiring diagrams as well as in the comprehensive
witing diagtams. The colour codes can also be used
in various combinations, e.g. BL/YRD, GLVT, etc.
Code Colour
BL Blue
BR Brown
GL Yellow
GN Green
GR Grey
OR Orange
RD Red
SV Black
VL Violet
VT White
Cross-sectional area of the conductor. The cross-
sectional area of the conductor is specified in square
millimetres (mm). The current that the cable is capa-
ble of carrying is dependent on the cross-sectional
area of the conductor,
Abbreviations
The Manual includes the following abbreviations:
AG
AIC
APC
AUT
CAB
CONV
D
EZK
|
LH
LHD
LHF
LHR
LHS
MAN
Pp
+
TSI
RHD
RHF
RHR
RHS
Air Conditioning
(Automatic Idling Control) Automatic adjust-
ment of the engine idling speed
(Automatic Performance Control) Automatic
control of the turbocharger boost pressure
Automatic transmission
Cabriolet
(Convertible) Cabriolet
(Driver) Driver's side
{Elektronische Ziindung mit Klopfkontrolle)
Breakerless ignition system with knock sen-
sor
Injection engine
(Luftmassenmesser Hitzdraht) Air mass
measurement by means of a hot filament
Left-hand drive
Left-hand front
Left-hand rear
Left-hand side
Manual gearbox
Passenger side, co-driver's side
Turbocharged engine
Timing Service Instrument
Right-hand drive
Right-hand front
Right-hand rear
Right-hand side
Example: T8 indicates that the engine is turbo-
charged and has 8 valves.
116 = 16-valve injection engine.
3-D = two-door Combi Coupe.
Saab 900
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a
12 Positive Supply
Positive supply
The +12 V supply of the car is distributed to the To enable these three connectors to be easily dis-
various consumers, etc. across an electrical distribu- tinguished, they are colour-coded.
id 152A = White
Cars which are powered by the 8-valve engine and are 152B = Red
destined for markets in the U.S.A., Canada and Japan 152C = Black
are equipped with a special Lambda relay box” for
; sae The pictur | i ins i
controlling the exhaust gas emission control-system. Picture Belew. shows Wie-tocatidheaattie-pine:in
the connector, viewed from the interior of the car.
Electrical distribution box
The electrical distribution box is easily accessible
and is located under the bonnet, on the left-hand
wheel housing. All of the fuses and most of the relays
are located in the electrical distribution box.
Item Lin the drawing of the electrical distribution box
is the socket for the Timing Service Instrument (TSI)
and item M is the holder for spare fuses.
Five cable harnesses are connected to the electrical
distribution box. The front and rear cable harnesses
in the engine compartment are connected directly to
the electrical distribution box, whereas the cables to
the facia and to the rear of the car are connected
across three 29-pole connectors designated 152A,
152B and 152C. These are permanently mounted on
the bulkhead between the engine compartment and
the interior of the car.
Rear cable
age: oe 452A WHITE |
Cable harnesses
for the instru- 1528 RED
ments >|
Rear cable nce
harness in the eine BLACK _—
engine compartment ae
Front cable harness
in the engine compartment
Saab 900
Page 5
vO
Positive supply
© 6
Relays
Tne following tables show the locations of the relays
in the electrical distribution box. In addition to the
relays in the electrical distribution box, several other
relays are located in different places in the car. The
locations of these relays are specified in the corre-
sponding sub-system descriptions.
Europe and other markets
Relay Component Function Remarks
location number
A,B 8 Headlamp full beam
and dipped beam
6 14:3 Heater element for the With timing function on
rear window certain markets
D 147 Ignition pulse amplifier
E 2a Ignition switch
EG 102 Fuel pump T8
G 102 Fuel pump Ig
H 156 AC compressor Air conditioning
J 155, Radiator fan for AC Air conditioning
K 68 * Horn
78 Dim dipped beam (GB)
259 Dim dipped beam (GB)
USA, Canada and Japan
Remarks
Relay Component Function
location number
A,B 8 Headlamp full beam
and dipped beam
C its: Heater element for the With timing function on
rear window certain markets
D 147 Ignition pulse amplifier
2 21 Ignition switch
F 270 Shift-up indication
G { 102 Fuel pump 18 Lambda
107 Extra fog lights 116 Lambda, T16 Lambda
H 156 AC compressor Air conditioning
J LOO Radiator fan for AC Air conditioning
K 68 Horn
cilia Motor drive for passive
seat belts
Saab 900
Page 6
14 _—s~Positive supply
Fuses The fuses are of blade type and, together with the
The locations of the fuses are shown in the illustra- connectors used, cause a lower voltage drop in the
tion of the electrical distribution box. system than the earlier fuse type. In addition, the
fuses are more resistant to corrosion.
Fuse
No. Rating Function
1 - Spare
2 30A Rear window regulators, Convertible
(1988)
3 30A _ Rear window regulators, Convertible
(1987)
4 10A _ GShift-up indication (US), dim dipped
beam (GB) Colour-coding of the blade fuses:
5 15A_ Brake fluid warning, windscreen
wipers, headlamp wipers, seat belt re- Colour Rating
minder lamp and EXH warning lamp
6 30A Air conditioner (AC) a ops : 0
7 15A _ Direction indicators, tachometer,
* : Yellow 20A
warning lamps for battery charging Transcafant 35.4
and choke pe er 30 A
8 10A Headlamp wipers, rear-view mirrors,
« Cruise Control 1)
9 30A __ Ventilation fan
10 10A APC system, lighting for controls, Checking the blade fuses
glove compartment illumination
11 30A _ Window regulators, sunroof
12 20A Electric heating pads for the front
seats, delayed interior lights
13 20A_ Reversing lights, cigarette lighter
lighting
14 15A __ Right-hand headlamp, full beam all
15 15A Left-hand headlamp, full beam and
full beam warning lamp
16 15A _— Right-hand headlamp, dipped beam
17 15A Left-hand headlamp, dipped beam oo
18 10A _ Right-hand parking light, right-hand
rear light, number plate illumination
Every blade fuse has test tappings, so that it can be
checked without the need for removing it from the
fuse box. If both tappings are live, the fuse is intact.
19 10A Left-hand parking light, left-hand rear /
light When the fuse has been removed, it will be clearly (
20 15A_ Radio visible whether or not the fuse wire has melted.
21 15A _ Rear fog lights, extra fog lights (US,
CA)
22 10A Fuel system, ignition system, tem-
perature gauge, handbrake warning
lamp
23 - Spare
24 10A _— Central locking
25 30A _ Radiator fan
26 25A _ Horn
27 15A — Hazard warning lights
28 15A _ Interior lighting, clock, radio, electri-
cally operated aerial
29 20A __ Heater element for the rear window
30 20A _— Fuel pump forthe fuel injection engine
18, T8, 18 Lambda, T8 Lambda
31 15A _— Brake lights
310D25A __s— Passive seat belts
310P25A Passive seat belts
Saab 900
Page 7
Positive supply 15
hithe Lambda relay box, USA and other
ate markets
Cars delivered to the U.S.A., Japan and Canada are
equipped with the Lambda system which is described
in detail in Group 2:3 of the Service Manual. The relay
box of the Lambda system shown here contains the
following relays:
Relay Component Function location
No.
A ~ Spare
B
106 Time delay relay
c
— D 107 Extra fog lights »
7 | E 105 Engine speed relay, manual
= 104 Hot start relay
G 138 Engine speed relay, Turbo
H - Spare
7 ») Relay D is fittéd only to cars equipped with extra
fog lamps.
Fd Lambda relay box, Europe
ct. See the section entitled "Cl fuel system’, pages
62-63.
sarly 0
Saab 900
Page 8
16 Positive supply
Ignition switch and positive
supplies
The supplies provided in the car are designated ”+”,
followed by a digit combination. Some of these sup-
plies are live only on certain occasions, such as when
the engine is being started or when the car is trav-
elling.
The positive supplies are as follows: +30, +X, +15,
+54, +50 and +S. The +30 supply is taken directly
from the battery, and the components supplied from
"+30" are therefore permanently energised. The
other supplies are taken from the ignition switch and
are dependent on the ignition switch setting.
Note that the numerals in the designations have
nothing to do with the system voltage.
Ignition switch
The ignition switch has four positions:
L Locked position
P Parked position
Oo Drive position
iS) Start position
The table below shows the ignition switch terminals
which are live in the various positions of the ignition
switch. The incoming supply (+30) from the battery
is connected to terminal 30.
Position
Circuit closed
between... L. P Oo S
30—X ER AE TATA!
30-54 —
30-50 Eee
30-—S?) ERAS ASCE TE TET
1) Although all ignition switches have terminal S,
this terminal is only used on cars destined for the
U.S.A. and Canadian markets.
Example: Terminal 15 is live in the drive and start
positions.
The picture below shows the terminals of the ig-
nition switch.
ak
eee
U.S.A. and Canadian markets
On these cars, terminal S is used for the ignition key
warning system. The terminal is always energised
when the key is in the ignition switch, regardless of
its position.
Distribution terminals
The following four spreads show the consumers/com-
ponents that are supplied from the following distribu-
tion terminals:
@ Distribution terminal +30
@ Distribution terminal +X
®@ Distribution terminal +15
@ Distribution terminal +54
The various consumers are supplied either directly or
across fuses.
The wiring diagrams show all components which are
supplied from each distribution terminal. Some com-
ponents are thus not included on certain markets/
versions.
No wiring diagram is shown for distribution terminal
+50, since this is used only for a few sub-systems.
The terminal is live only when the ignition switch is in
the start position, and this is described in the corre-
sponding sub-system description. For particulars of
distribution terminal +S, see the section entitled
"Instruments and warning systems — Seat-belt and
ignition switch warning”.
Saab 900
Page 9
18 Positive supply
Distribution terminal +30
RD 25.0
ot 30
RO 16.0 50 =:
D15a
BL 250 BL 16.0
211 7 6 RD 10.0
75
10 VT 60
559 RD 25
b: 823 10
SS9A RD 25 GR 25 VT 40
$598
559C RD 10 RD OS 823A RD 25
Loy U
30 4 30 30 86
21 LH24 $200 102 229% 310P 290
M88:116\ | 116,116,116, T16X 42 US : 18d, 116% CAB
SB SA 5
GR 4.0 GR 4.0 GR 4.0
152B
7A GR 10 fe +} TA GR 1.0 30 10
sik ®@
280 GR 1S 20 GR 15 wae 7 GR 2S [25.] 7GR25
. Suen aa SS 30
°) kon
30
8
20
SK SH 5G SE SF so SC 475 695
GR 25 JGR 15 GR 0.75 JGR 1.5 GR 15 GR 1S JGR 10 GR 1S BL 0.75
5M GR1S ae,
1 a.
|
% l}: [ls all] al] of 23] |] ]30 l 31122A li [224
1
fed fol fol fel 2 J [p22
116 |C8,18 289
116\} 18d
Ti6 | T8
T16\} TB US, CA US, CA, JP
Saab 900
Page 10
Positive supply 19
Operation
The positive supply is taken from battery 1 directly to
starter motor 4 and then further to B+ on alternator
2, and to distribution block 75.
From distribution block 75, supplies are then taken
to the following components and to fuses 24—31.
(Fuse 23 is not used on cars powered by the 16-valve
engine.)
@ Ignition switch relay 21
@ Timing service instrument socket 73
@ Fuel pump relay 102, control unit 200 and main
relay 229 for the LH fuel injection system on cars
powered by the 16-valve engine. (On cars with the
8-valve fuel injection engine, fuel pump relay 102
is connected instead to fuse 30.)
e Lighting relay 8
e@ Light switch 10, across 29-pole red connector
152B
@ Ignition switch 20 and connector 122 for the bur-
glar alarm, across 29-pole white connector 152A.
e@ Fuses 310P and 310D for the passive seat belts on
cars destined for the US market (cars with 18 or 116
engine).
e@ Fuse 290 (for the Convertible top)
On cars destined for the U.S.A., Canada and Japan,
fuse 21 for the extra fog lamps (US, CA) and connec-
tor 289 for the burglar alarm (US, CA, JP) are also
connected to this distribution block.
Fault-tracing hints
1. Check the battery voltage.
2. Check the terminals of distribution block 75 and
29-pole connectors 152.
Check that the supply to each component is live.
4. Check the relevant wiring.
Saab 900