Page 11
20
Positive supply
Distribution terminal +X
M87
! 75 ears
7 ]_R0 16.0 Faq R40 7 R25 F947 cR 25
. 16.0 fk 25.0
7 211
126
37 GR/RD 1.5 99 q-3Z_GR/RD 1.5
SE, Fl, EU, GB,
ME, FE, AU
° SOA _RD_0.75 RD 1.5 RO 0.75
0 1 Zz
5 30 _ X fo}
le 22K a l 5 Bh22
by, 289
588 ow)
5 @ 58 S US, CA, JP
10
M88
! 75 C4
+P 8218.0 py 5 GR 40 » 7 oR25 Food 7 or 25
FE 30
. 16.0 i 25.0 20
7 211
X
152A RD 2.5
30B RD 1.5 30B RD 1.5
30A RD 1.5 > qf SOA RD 1.5
sees 30¢
GR/VT 1.5
SE, Fi. EU,:GB, 3158
ME, FE, AU
12B_GR/VT_0.5 ORT 1.5 co ws
0 1 2
S $30 . xX
[[pot224 es he
bt, 289
58B 0
N
1 @ |, (S) US, CA, UP
10
Saab 900
Page 12
Positive supply 21
Operation Fault-tracing hints
The positive supply is taken from battery 1 to ignition 1. Check the battery voltage.
switch 20 across distribution block 75 and 29-pole 2
while comnemoriaek Check the terminals of distribution block 75.
3. Check the terminals in 29-pole connectors 152
and 12-pole connector 58. The latter is located
below the facia, to the left of the steering wheel
When the ignition switch is set to the parked, drive or
start position, terminals 30 and X of the ignition
switch will be interconnected. The +X supply will
then be connected to fuse 20 and light switch 10. (behind the knee shield).
On certain markets, the +X supply is also used for 4. Check that the supply to each componentis live.
the burglar alarm (connector 289). 5. Check the relevant wiring.
~
Saab 900
Page 13
22
eC
Positive supply
Distribution terminal +15
M87 aoe
1 Axo As
5 Ro 16.0 gy 5 GR 4.0 7GR 2.5 29q-2 GR 2.5
BL 16.0 |BL 25.0
7 211 123 GN/VT_1.5_} 5,4 123 GN/VT 1.5
123H| 123¢ 123k
GN/VT 1.5 GN/VT 0.75 GN/VT 1.0
(C8, 18, 18, T8,
I
Ie 22A
650 652
GN/VT 1.0 GN/VT 1.0 Eee 10 306
(gga) (466A). US:1B A116
15
ry
5 146 176 1236 1528
116, 116A pee ors fpf uzae Oust or 10. 147A,47B,47C,
3 47D,47M
159 159 159
+15 HIS Fle | +15
GN/VT 1.0
ial 18,18 _T8,T8A
3 4 2 5 us 52¢
S| Ps) a r) 123A 1 <t
5 5 | 5 BL/RO 0.75 [5] 1234 BL/RO 0.5
FA ~ Ss 5 546 123N
fc) a 6 GN/VT 0.75 |GN/VT 0.75 144
2 oy Py Fr 123F
8 a] 8 8
GN/RD 0.75} 4 123F GN/RD 0:5
218 GN/VT 0.5 pz BL/RO_0.75 \ Uy, =
1
15 15 15 1 18 15
26 113 156 114 140 147 200 102
a> a> AC c8 c8 116,116)
= =a 116, T16A
uj <uj eae
ou ow
vu “uu
am a
M88
! 75 52A
TR 16.0 pa 5 cr 4.0 x 7 GR 25 nodZ GR 25
C4 30
} 20
BL 16.0 JBL 25.0
123€ GN/VT_1.5
7 211 f 123, GN/VT 1.5 28 123 GN/VT 1.5 NS
| I an = eN/VT 0.75
C8, 18, IBA, | 116 GN/VT 1.0 GN/VT 1.0 e
T8, T8A, T16, T16\ S157
(ll: 22A [l} 22A 73 [He 22A SE ae.
12
123H| 1238 652 650 123M 306
GN/VT 1.5 GN/VT 0.75 GN/VT 1.0 IGN/VT 1.0 GN/VT 1.0 US: IB AI16A
vault Sh : 1528
1236
Ss Ves hs 520 GN/VT_0.75 [94.1236 GN/vT 0.75 |8 47A,47B,47C,
47F,47M
159 159 159
+15 lee alee | +15
IGN/VT 1.0 —$—_ \\_-_—_—__——
. ; 48.18, T8,TB\
9 S e h23A 52C
= a 546 BL/RD 0.75 ese 123A BL/RD 0.5
= & GN/VT 0.75 123N
bs a T 0.75
| 3 6 igi 123F tet
> 3 T16,T16A GN/RO 0.75} 55 4.123F GN/RD 0.5)
382A BL/RD 0.75 l pe iia egeae
ol
15 18 35 15
26 113 156 114 140 200 200 102
a2 a2 AC C8 C8
<ui fui
Ou Ou
wu wu
vie am
Saab 900
Page 14
6 <¢
Positive supply 23
Operation
The positive supply is taken from battery 1 to ignition
switch 20 across 29-pole white connector 152A in
the electrical distribution box.
When the ignition switch is in the drive or start posi-
tion, the +15 supply will be taken from terminal 15 of
the ignition switch to the following components:
@ Timing service instrument socket 73
e@ Amplifier 146 for the electronic ignition system
@ Control unit 176 for the EZK ignition system
@ Ignition coil 5
@ Fuse 22
@ Control unit 306 for the passive seat belts, across
3-pole connector 57 (cars for the US market, with
18 or 116 engine)
The following components are then supplied from
fuse 22, across distribution terminal 159. Some of
the components are included only on cars for certain
markets, on cars with 8 or 16 valve engines, etc.
@ Time-delay relay 26 for the radiator fan
@ One half of the combined instrument 47
@ Ignition pulse amplifier 147 (1987 model)
@ Relay 156 for the AC compressor
@ Relay 113 for the electrically heated rear window
@ Carburetor float chamber valve 114
@ Carburetor fuel shut-off valve 140
@ Control unit 200 for the LH fuel system (67 =
6-pole connector in the engine compartment, to
the right beside the air intake)
@ Fuel pump relay 102 (18, T8). On turbocharged
cars, the relay is connected across boost pressure
switch 144.
e@ Fuse 3 (1988 model)
@ Ignition coil 320 with integrated amplifier (1988
model)
Fault-tracing hints
1. Check the battery voltage.
2. Check the terminals of distribution block 75 and
29-pole connectors 152.
3. Set the ignition switch to the drive position and
check that the supply from fuse 22 is live.
4. Check the relevant wiring.
Saab 900
Page 15
24 ‘Positive supply
Distribution terminal +54
1
RD 16.0
a 30
t 20
BL 16.0 |BL 25.0
7 211 12 GR/VT 0.75 fea | 12 GR/VT 1.0 54
30, 86
sg BS
87] 8
13
SV 0.5
[77158
1 1D 11H
VT 2.5 VT 2.5 VT 2.5
.
VIN IA I TE ae IG oe Mies Ita cesta 117B
VT_2.5 IVT 2.5 |vT 2.5 |vT 2.5 |vT 2.5 Ivt 2.5 Ivt 25 vt 25 vt 25 lvT 25 VT 0.5
! | 86
| Fas ]
CAB
1
RD 16.0 polities 5 GR 4.0
Br =—
= 10
16.0 fk 25.0 Ae
Ry 211
O 7 GR 25 b 29d
152A
152A
7 GR 25
y 86
21
aes
i
13
SV 0.5
12 GR/VT 0.75 pee 12 GR/VT 1.0
1" 11D 11H
VT 2.5 VT 2.5 VT 2.5
1"
VT 2.5
59
11_VT_2.5
f
“AS MB? SeIN Tata oles lee iemeine Stee lak iat lin 1178
M88 _M87 VT_2.5 |VT 2.5 IVT 2.5 VT 2.5 |vT 2.5 |vT 2.5 |vT 2.5 IvT 25 |vt 25 IvT 25 VT 0.5
I | 86
]
Saab 900
Page 16
Positive supply 25
Operation Fault-tracing hints
The positive supply is taken from battery 1 across 1. Check the battery voltage.
ee 2. Check the terminals of distribution block 75,
@ the contacts (terminal 30) of ignition switch relay and check that terminal 30 of ignition switch
21 relay 271 is live.
® terminal 30 of ignition switch 20 and then onto —3._— Set the ignition switch to the drive position and
the coil of ignition switch relay 21 check that ignition switch relay 21 operates.
When the ignition switch is set to the drive position, Terminal 87 of the relay should then be live.
terminals 30 and 54 of the ignition switch will be 4. Check that fuses 4—13 in fuse holder 22A are
interconnected. Current will then flow through the j live (fuses 2-13 on the Convertible)
coil of ignition switch relay 21 across 29-pole con- i
nector white 152A, and the relay will be energised. 5. Check the relevant wiring.
The relay contacts will close, and current will flow
through the three distribution blocks 192 to fuses
4—13 in fuse holder 22A (fuses 2—13 on the Convert-
9 ible).
The contacts of horn relay 68 will also be energised
when the ignition switch relay has been energised.
Saab 900
Page 17
Earth connections
27
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
Coupe, the Sedan and the Convertible.
Earthing point in the facia
Earthing point on the radiator cross-mem-
ber
9 Earthing point in the luggage compartment
65 Earthing point under the back seat
93 Earthing point on the amplifier
117 Earthing point at the handbrake lever (1987
model)
Earthing point between the ignition switch
and the handbrake lever (1988 model)
158 Negative distribution terminal in the electri-
cal distribution box
201 Earthing point, engine (two)
211 Earthing point, gearbox
257 Earthing point, alternator bracket
“Ww
The battery is earthed by means of a 16 mm? conduc-
tor 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.
Earthing point 65 is used only on cars with passive
seat belts.
Saab 900
Page 18
28 Earth connections
LLL
Earthing point 3
2a
SE, Fi, EU, GB sig
Sv ana S 124
373 Sv 075 2161
ME, FE, AU Pag
maf
Sv OF 4 124
373 Sv O75 > 98
MiZA 5Y 0.75 210
n2]
US, CA, JP SV 075L_ 4194
22 SY 0.75 Pil
= 23
sy o af ss 83
69 Sv O75 225
435 $v O75 38 (MBs)
193. S¥ O75 £18, 16, 47G, 47H, 47u, 47K, 49, 110
4
: ai {maz —* 474, 47C, 47F, 471, 47L, 47N, 47S
: \MaB—2474, 470, 471, 47N, 475
L__ 480 sv 075 5 8B
22 Sv O73 +125
806 Sy 0.75 128
$15 $v 1.0 8
aa 131
sv 0 te t 132
|__B16C Sv O75 — 2h sx Sv 07S 133
St6C Sy 9.79 ey £160 SV 0.75 134 (AUT
143
bt OO_ SY 0.75. 169
_JiN8 Sy 0.75 148
48
16
153
SE, Fl, EU, ME,
US, CA, JP 154
128 Sv O75
48
——~
sv Ps 16
63 S¥ O75 153
62 SV O7S 154
148
GB, FE, AU sv bas
160
127
207 (M83:US, CA)
36
1070 $v 29 74
773
Saab 900
Page 19
Earth connections 29
Components connected
Earthing point 3 is located to the left of the steering
wheel, below the facia, behind the knee shield (on
the front side of the instrument cross-member, be-
hind 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
18
23
25
36
eo:
47
48
49
> 7
83
88
98
110
116
124
125
127
Light switch
Combined instrument lighting
Flasher relay
Hazard warning light switch
Motor for the ventilation fan
Motor for the AC recirculation valve (1988
model)
Combined instrument
Cigarette lighter
Clock
Resistor (half-speed) for the ventilation fan
Relay for intermittent operation of the wind-
screen wipers
Switch for extra fog lamps (US, CA)
10-pole connector
Tachometer
Switch for the electrically heated rear win-
dow
Switch for the left-hand electrically oper-
ated rear-view mirror
Switch for the right-hand electrically oper-
ated rear-view mirror
Motor for the right-hand electrically oper-
ated rear-view mirror (across 4-pole con-
nector 123 in the engine compartment at
the right-hand door pillar and in the right-
hand door)
128
131
132
133
134°
143
148
153
154
160
161
169
207
Cruise Control relay
Electronic control unit for Cruise Control
Sensor for the speed transmitter
Clutch switch for Cruise Control (across a
2-pole connector under the facia on the
left-hand side)
Brake switch for Cruise Control (AUT) (across
a 2-pole connector under the facia on the
left-hand side)
Recirculation switch, AC
Ashtray illumination (across a 2-pole con-
nector in the facia)
Lighting for the cigarette lighter
Lighting for the heater controls
Switch for glove compartment illumination
Switch for the rear fog lights
Switch, AC
Electrically-heated rear-view mirrors (1988
model: US, CA)
Saab 900
Page 20
30 ~=— Earth connections
Earthing point 7
28 sv15 1, 12 (LHS)
29 SV. ES 11, 12 (RHS)
1494 SV 05 13, 118 (RHS)
149 SV O05 28 (RHF)
234 (RHS)
1498 SV 05 119 {RHS)
149 SV 0.5 13 oe A
28 (RHF
n2 5V 25 29, sv 37 e
92 Sv 0.75 263
99 S¥ 0.75 oh vy
“e15}"-—" 66 (LHS)
994 Sv 0.75 ees Y=. 66 (RHS) t
472 $V 1.0 85 (LHS)
470 Sv 1.0 85 (RHS)
18,78: ME, FE
1054 SV 0.75 130
3 Sv 25 158
H2a $V 25 _ 28, Sv 172
482 Sv 15 1479
M87:18A (SE, EU)
410 SV OS > 106
4108)
sv os)
+105 (MAN)
M87: T8A (SE, EU)
419 5¥ 05 = 106
~
sv 0.5
+438
I8A:US, CA, JP, AU
410 SV 0.5 = 104
4104
sv a5
2105 (MAN)
4
Sv 0.
2406
1
+
| BL 16.0 se
BL 25.0
4777 211
Saab 900