Page 1
Earth connections
2/
Earth connections
General
The car has certain earthing points which have ”com-
ponent numbers” and other earthing points at which
the component is earthed directly to the chassis,
such as temperature transmitters, oil pressure trans-
mitters, etc. The locations of the earthing points with
component numbers are the same in the Combi
Coupé as in the Sedan.
3 Earthing point in the facia
7 Earthing point on the radiator cross-member
9 Earthing point in the luggage compartment
65 Earthing point at the handbrake lever
158 Negative distribution terminal in the electri-
cal distribution box
On the 1984 models, the negative pole of the battery
is earthed by means of a braided conductor connect-
ed to earthing point 7 on the radiator cross-member
below the radiator fan. The engine is also earthed by
means of a braided conductor connected to earthing
point 7.
On the 1985 - 1986 models, the battery is earthed by
means of a 16 mm? conductor to earthing point 7.
The engine is connected directly to the negative pole
of the battery by means of a 25 mm? conductor.
From earthing point 7, a cable then runs to distribu-
tion terminal 158 in the electrical distribution box on
the left-hand front wheel housing.
In addition, cars with fuel injection system are provid-
ed with a reference earthing point 201. This is loca-
ted on the cylinder head of the engine, beside the
lifting lug.
Page 2
Earth connections 29
Components connected
Earthing point 3 is located to the left of the steering
wheel, below the facia, behind the knee guard (onthe
front side of the instrument cross-member, behind
the flasher relay).
The following components are connected (by means
of screw terminals) to this earthing point. Some of the
components listed below are fitted only to cars of
certain versions or for certain markets.
10
23
25
36
47
48
74
83
88
116
124
125
127
128
131
132
133
143
148
Light switch
Flasher relay
Hazard warning light switch
Motor for the ventilation fan
Combined instrument
Cigarette lighter
Resistor (half-speed) for the ventilation fan
Relay for intermittent operation of the wind-
screen wipers
Switch for extra fog lamps
Switch for the electrically heated rear win-
dow
Switch for the left-hand electrically operat-
ed rear-view mirror
Switch for the right-hand electrically operat-
ed rear-view mirror
Motor for the right-hand electrically operat-
ed rear-view mirror (across the 4-pole con-
nector 123 in the engine compartment at
the right-hand door pillar and in the right-
hand door)
Cruise Control relay
Electronic control unit for Cruise Control
Sensor for the speed transmitter
Ciutch switch for Cruise Control
Recirculation switch, AC
Ashtray illumination (across a 2-pole con-
nector in the facia)
153
154
160
161
169
267
Lighting for the cigarette lighter
Lighting for the heater controls
Switch for glove compartment illumination
Switch for the rear fog lights
Switch, AC
Earthing of the radio installation (across
2-pole connector 59 or 10-pole connector
98)
Page 3
Earth connections 31
Components connected
Earthing point 7 is located below the radiator, on the
right-hand side of the radiator cross-member. The
following components are connected (by means of
screw terminals) to this earthing point. Some of the
components listed below are fitted only to cars of
certain versions or for certain markets.
Negative distribution terminal 158 in the electrical
distribution box is also connected to earthing point 7.
LH = left-hand side
RH = right-hand side
411
12
13
26
20
28
37
63
66
81
85
93/118
119
130
158
172
179
234
Headlamp full beam
Headlamp dipped beam
Parking lights
Time-delay relay for the radiator fan
Direction indicator lamp, left-hand front
Direction indicator lamp, right-hand front
Radiator fan motor (across 2-pole connector
59 at the radiator)
Washer motor (across 2-pole connector 59
on the right-hand side of the engine com-
partment, beside the washer fluid container)
Headlamp wiper motor (across 3-pole con-
nector 57 in the engine compartment at the
corresponding motor)
Driving lights
Extra fog lamps
Corner lights/driving lights
Side reversing lights
Coolant temperature switch
Negative distribution terminal
Radiator fan for the AC (across 2-pole con-
nector 59 at the radiator fan motor)
Solenoid valve for the APC system
Side marker lights
Cars with 8-valve engine for the U.S.A., Canada
and Japan
104 Hot start relay
105 Engine speed relay
106 Time-delay relay
138 Engine speed relay
Throttle valve angle transmitter
203
Page 4
Earth connections 33
Components connected
Earthing point 9 is located under the spare wheel
hatch in the luggage compartment, at the extreme
rear on the centre member. The following compo-
nents are connected (by means of screw terminals) to
this earthing point. Some of the components listed
below are fitted only to cars of certain versions or for
certain markets.
LH = left-hand
RH = right-hand side
46 Fue! level transmitter (across 3-pole connec-
tor 57, under the luggage compartment
floor, beside the transmitter)
101 Fuel feed pump (across 3-pole connector 57
under the luggage compartment floor)
103 Fuel pump (across 3-pole connector 57 un-
der the luggage compartment floor)
177 Control unit for the APC system
Combi Coupé
The tailgate lighting is earthed to the tailgate which,
in turn, is earthed to earthing point 9 across cable
211A SV 2.5 (across 3-pole connector 57 in the
luggage compartment, at the left-hand air outlet).
14 Rear lights
15 Number plate illumination
27 Direction indicator lamps, left-hand
28 Direction indicator lamps, right-hand
30 Brake lamps
32 Reversing lamps
33 Rear fog lights
109 High-level brake lights (across single-pole
connector 60 in the tailgate, at the left-hand
rear light cluster)
Sedan
14
15
27
28
30
32
33
Rear lights
Number plate illumination (across 3-pole
connector 57 in the luggage compartment,
to the left below the parcel shelf)
Direction indicator lamps, left-hand
Direction indicator lamps, right-hand
Brake lamps
Reversing lamps
Rear fog lights
Page 5
53
64
82
121
151
162
-163
89
-190
“191
Earth connections
35
Components connected
Earthing point 65 is located between the left-hand
front seat and the handbrake lever. The front seat
must be removed before access can be gained to the
earthing point.
The following components are connected (to the
handbrake switch mounting screw) to this earthing
point. Some of the components are only fitted to cars
of certain versions or for certain markets.
43
53
64
82
121
151
162
163
175
181
183
189
190
191
288
Handbrake switch
Interior lighting switch
Heating pad with thermostat (across 2-pole
connector 59 under the corresponding front
seat)
Seat belt/ignition switch warning relay
Seat switch for the heating pad (across
2-pole connector 59, under the right-hand
front seat)
Time-delay relay for the interior lighting (ac-
ross 4-pole connector 123 under the back
seat, to the left beside the relay)
Switch for the driver’s door electric window
regulator
Switch for the co-driver’s door electric win-
dow regulator
Electronic unit for the central locking system
Switch for the electrically operated sunroof
Control unit for the central locking system,
RH drive cars (across 3-pole connectors
57R in the right-hand front door and forward
of the right-hand A-pillar, beside the upper
hinge)
Switch for the rear-door electric window re-
gulators
Switch for the left-hand rear electric window
regulator
Switch for the right-hand rear electric win-
dow regulator
Burglar alarm switch (US)
Page 6
Earth connections 37
Components connected
Distribution terminal 158 consists of a ring of flat pins Cars with 8-valve engine
and is connected to earthing point 7 on the radiator 8 Lighting relay
cross-member by means of cable 3 SV. 102 Fuel pump relay
The terminal is located on the underside of the elec- 104 _— Hot start relay
trical distribution box. The following components are 113 _ Relay for the electrically heated rear window
connected to the terminal. Some of the components 155 Relay for the AC radiator fan
listed below are fitted only to cars of certain versions 270 _—_ Shift-up indication relay
or for certain markets.
. ith 16-valve engine
7 Earthing point on the radiator cross-member aie iin Aiea 8
21 Ignition switch relay 8 Lighting relay
38 Recirculation valve 113 Relay for the electrically heated rear window
62 Windscreen wiper motor 155 Relay for the AC radiator fan
73 ‘Timing service instrument socket 270 — Shift-up indication relay
89 Side direction indicator, left-hand
90 Side direction indicator, right-hand
104 Hot start relay
126 Motor for the left-hand electrically operated
rear-view mirror (across 4-pole connectors
123 in the engine compartment at the left-
hand door upper hinge and in the left-hand
front door)
147 Ignition pulse amplifier
156 Relay for the AC compressor
183 Control unit for the driver's central door lock
(across 3-pole connectors 57 in the engine
compartment at the left-hand door upper
hinge and in the left-hand front door)
Page 7
38
Starting system
BL25
300
50
RD25
75
Starting system
152A
AA_1GR25 "29. |] 7GR25
i>
30 Pp
Ly 48
50
—
122 GL/RD 25 P
R
7s
122 GL/RD 2.5 :
152A lan AF
122AGL25 [-27_] 122 Gi/rd25
|
fe 1
M1984 = =M1985 = M1986
122A 122,22
GL25 }GL25 |aLz5
le 0B
2 9123
122A “122A
Gi25 |ai25
l ae
GL 25
l6q
Page 8
60
Cl fuel system with Lambda, 1985 models
Cl fuel system with Lambda, 1985 models
+30
+30
152A
ha 15 123K _GN/VT_1.0 123 GN/VT 15 [,28,] 123, GN/VT 15
]
Q 224 {fo I
: Lil
260
M BR 25
262A 261A 4
SV 15 101 GR 15
5 12bA
BL 15 —
S9 oes
TURBO 122A _Gt_2.5 [27] 122 Gu/RD 25
—L 12
ee *
| 23
2
262A 261A s 123A
SV 15 GR 18 5 Bear TS 78%
al L ¥ i
, : ps aos
Fa
M = a 123F
262 261 . GN/RD 0.75
sv25] 103 |or 25 Ent
qe IL 284A
it BL 0.75
30 5
59 318] 2844 BL 0.75 oo
[aa
262 SV 25 oe He 102 = is 282A GL_0.75
SOW 1228 GL/RD 15 122 GL _25
87 Se UREU
Fi Vor eA Te 2840 BL_075 +30
cr/ro 1s {GR 25 SV 0.75
152A RD 25
257] 261 GR/RD 25 i cee: Meee
[F758 i Fe 30 271 GL 10
59 #3
357 VL/VT 0.75 361 GR 0.75 ite 19 97
353 GL/RD 15 ee ec panama tS ae 67 ony BR 045
y) | (|: !22 2710
l J BR O78 413A GN 0.75
PK 136 | F139 ies wn
iN oR 075 VT 0.75
267 GR_0.75
356 354 ¥
GN 10 VL 0.75 ‘ 95 9 : oy
a 6 Z)260 GN 0.75
<7) 356a 266 268 '
SV 0.75 SV 0.75 495
+ + ea 59 RD 0.75
2, 4 5 RO/VT 0.75
362 BR/VT 0.75
-----2 |o2
TEST
26q
442
GL 0.75
avd 361 GR075
———_ — qm me Ge ee ee ieee cee eee eee eee oe
282A GL_0.75
il 355 RD/VT 0.75 361C GR_0.75 3618 GR O75 273C_GN 0.75,
497 BR/VT 0.75 2828 GL O75 |
435 | 87 15 87 1S PX2 2 7 Trip TTKK 150 50 "
3181 2848 BL O75 [318 f
| cl IL | 438 n 106 J ed 104
105 - B 108
| 30 31 ral 31 30 783! TRK 31
Rs10c 410D SV 0.75
[sv075 410B SV 0.75 AY iY \ 410A SV 0.75
a 440 GL/RD 0.75 oe RO/VT 0.75
a | 412 RD 0.75
6 5 |
_———— fee SS EE EE GE GS GS
351 352 422 494 410
SV/VT 0.75 BR 0.75 SW/VT 0.75 RO/VT 075 SV 0.75
3
203
498
SV 0.75
Saab 900
Page 9
76
Ignition system with tachometer and timing service instrument socket — 1985
ignition system with tachometer and timing
service instrument socket — 1985 models
+15
!
:
123
GN/VT 15
Tan
EN, 123K
GN/VT 1.0
1230 13H 123C r i
GN/VT 10 |GN/VT 15 GN/VT 0.75
t le
123M
GN/VT 1.0
1236
GN/VT 0.75
3 paD =
22.) 182 BL_0.75
ry oF U
124A BL_15 124 BL 15
1 V a
204 GL/VT 0.75 :
Pats
146 i
: 3 |; was Lo ae ot
4 : socr b+ |. 152B
( Nes
{ 201 BR hg, 2 204
4 6 GL/VT 0.75
393
4 g y : Svs p31 1102
157
284A
284 BL 0.75
BL 0.75
r
I 16V 8
[0
284A
i 1230 GN/VT 1.0 BL 0.75
4 67/123
sp 22 GL 25 122 GL_25
e—
By 6a
304
RD 25
1
RD 16 SBGR4O A
alg 7
Saab 900
Page 10
075
ignition system with tachometer and timing service instrument socket—1985 77
Operation
This breakerless ignition system is equipped with a
Hall sensor.
When the ignition switch is in the start or drive posi-
tion, +15 is supplied to ignition coil 5 and amplifier
146.
The amplifier receives ignition pulses via a shielded
cable from the Hall sensor in ignition distributor 6.
The frequency of the pulses is equivalent to the en-
gine speed.
The pulses are amplified and adjusted in amplifier
146. Ahigh-tension pulse is produced in the second-
ary winding each time a pulse breaks the primary
circuit of the ignition coil. The high-tension pulse is
then supplied to the corresponding spark plug via the
distributor.
Tachometer 110 is supplied across fuse 22. The con-
trol pulses required for displaying the engine speed
are supplied from terminal 1 of the amplifier, via
timing service instrument socket 73.
Timing service instrument (TSI) socket 73 is intended
fora special ignition service instrument and has the
following terminals:
1. Positive supply direct from battery 1
2. Earth
3. Solenoid (terminal 50) on starter motor 4
4
Positive supply (+15) from the ignition switch
when the latter is in the start or drive position
5. Ignition pulses from amplifier 146
6. Not used
Fora more detailed description of each component in
the ignition system, see the Service Manual, 3:1,
Electrical system, Instruments.
Fault-tracing hints
The ignition system will be energised when the igni-
tion switch is in the drive position.
1. Check that terminal 15 on the ignition coil and
terminal 4 on timing service instrument socket
73 are live.
2. Check that terminal 4 on amplifier 146 is live.
Tachometer: Check fuse 22 first and check that
the supply to it is live. Check that terminal 3 on
the circuit board for tachometer 110 is live, and
that ignition pulses are being supplied from the
amplifier.
4. Check al! connectors, cable harnesses and
earth connections.
See also the fault-tracing section for each compo-
nent in the Service Manual, Group 3:1, Electrical
system, Instruments.
Locations of components
The locations of the components in the ignition sys-
tem with tachometer and timing service instrument
socket are the same on the 1984, 1985 and 1986
models. For particulars of the locations, see pages
80-81.
Saab 900