1983 FIAT UNO fuses

Torque wrench settingsNm lbf ft
Driveshaft flange connecting bolts (Turbo ie) . . . . . . . . . . . . . . . . . . . . . 43 32
Final drive output shaft bearing cover bolts (Turbo ie) . . . . . . . . . . . . . . 24 18
Intermediate shaft support to crankcase (Turbo ie) . . . . . . . . . . . . . . . . 48 35
Braking system (903, 999, 1108, 1116 and 1372 cc)
General
Note:The following items differ, or are additional to those specified in Chapter 8:
Master cylinder bore diameter:
903 cc, 999 cc, 1108 cc and 1116 cc . . . . . . . . . . . . . . . . . . . . . . . . . 19.05 mm
1372 cc ie . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.65 mm
Vacuum servo diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152.4 mm
Hydraulic push rod-to-master cylinder support plate clearance . . . . . . 0.825 to 1.025 mm
Braking system (1301 and 1372 cc Turbo ie)
General
System type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Four-wheel discs, ventilated front, solid rear. Vacuum servo. Pressure
regulating valve on rear brakes
Master cylinder bore diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.225 mm
Vacuum servo diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177.8 mm
Front disc brakes
Disc diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240.0 mm
Disc thickness - new . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19.9 to 20.1 mm
Disc thickness - minimum (refinishing) . . . . . . . . . . . . . . . . . . . . . . . . . . 18.6 mm
Disc thickness - minimum (wear limit) . . . . . . . . . . . . . . . . . . . . . . . . . . 18.2 mm
Minimum thickness of pad friction material . . . . . . . . . . . . . . . . . . . . . . 1.5 mm
Caliper cylinder diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48.0 mm
Rear disc brakes
Disc diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227.0 mm
Disc thickness - new . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.7 to 10.9 mm
Disc thickness minimum (refinishing):
1301 cc Turbo ie . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.7 mm
1372 cc Turbo ie . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.35 mm
Disc thickness - minimum (wear limit) . . . . . . . . . . . . . . . . . . . . . . . . . . 9.0 mm
Minimum thickness of pad friction material . . . . . . . . . . . . . . . . . . . . . . 1.5 mm
Caliper cylinder diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34.0 mm
Torque wrench settingsNm lbf ft
Front caliper cylinder housing mounting bolts . . . . . . . . . . . . . . . . . . . . 52 38
Front caliper support bracket bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 38
Front disc fixing bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 18
Rear caliper support bracket bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 18
Rear caliper cylinder housing mounting bolts . . . . . . . . . . . . . . . . . . . . 52 38
Electrical system
Battery
Turbo ie engine models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Ah
Fuses (903, 999, 1116, 1299/1301 and 1301 cc Turbo ie)
Fuse No. Rating Circuit
1 7.5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LH tail, RH front parking, rear number plate, check panel
2 7.5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RH tail, LH front parking, cigar lighting, clock light, heater control
illumination, map reading lamp.
3 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RH headlamp main beam
4 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LH headlamp main beam and warning light
5 25 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Radiator cooling fan, econometer and horns
6 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cigar lighter, courtesy lamps, digital clock, stop-lamp switch, clock
and radio
7 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RH headlamp dipped beam
8 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LH headlamp dipped beam, rear fog warning lamp and indicator
9 20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Heated rear screen and warning lamp
10 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Instrument panel, stop-lamps, direction indicators, reversing lamps
and warning module
11 20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Heater fan, fan control illumination and digital clock
12 20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Windscreen wiper, washer pump and rear screen wiper
13 - . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Spare
14 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hazard warning lamps and indicator
Supplement: Revisions and information on later models 13•15
13

Fuses (903, 999, 1116, 1299/1301 and 1301 cc Turbo ie) (continued)
Fuse No. Rating Circuit
Supplementary fuses at side of main fuse block:
A 20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Front fog lamps
B 30 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cooling fan (Turbo ie models)
C 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fuel injector cooling fan (Turbo ie models)
D 30 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Electric windows
E 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fuel pump (Turbo ie models)
Fuses (later 903, 999, 1108, 1372 ie and 1372 cc Turbo ie)
Fuse Rating Circuit
1 7.5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LH tail, RH front parking, rear number plate lamps and check panel
2 7.5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RH tail, LH front parking, cigar lighter illumination, clock light, heater
control illumination and map reading light
3 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RH headlamp main beam
4 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LH headlamp main beam and warning light
5 25 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Radiator cooling fan (except Turbo ie models) and horn
6 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cigar lighter, courtesy lamps, digital clock, stop-lamp switch, clock
and radio
7 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RH headlamp dipped beam
8 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LH headlamp dipped beam
9 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rear fog lamp and warning lamp
10 20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Heated rear screen and warning lamp
11 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Instrument panel, stop-lamps, direction indicators, reversing lamps,
warning module and carburettor cut-off (FIRE models only)
12 20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Heater fan, heater/ventilation control illumination lights and digital
clock light
13 20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Windscreen wiper, windscreen washer pump and rear wiper/washer
(where fitted)
14 20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Horns and relay
15 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hazard warning light and indicator light
Supplementary fuses at side of main fuse block:
A 30 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Electric windows
B 25 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Central locking (where fitted)
C 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Injector cooling fan (where fitted)
D 20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Headlamp washers (where fitted)
E 20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Foglamp and warning lamp
F - . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Spare
G 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fuel pump (fuel injection models)
-10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Heated Lambda sensor
Supplementary fuses on steering column relay bracket:
-10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Antiskid monitor circuit (where fitted)
-25 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Antiskid supply circuit (where fitted)
Steering and suspension
General
1301 cc Turbo ie
Castor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1º 55’ to 2º 35’ positive
Number of turns of steering wheel, lock-to-lock . . . . . . . . . . . . . . . . . . 3.42
Later models
Steering angles:
Camber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -30’ ± 30’
Castor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2º10’ ± 15’
Toe-in . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to 2.0 mm
1301/1372 cc Turbo ie
Steering angles of roadwheels:
Inner wheel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36º 43’
Outer wheel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31º 27’
Torque wrench settingsNm lbf ft
Anti-roll bar clamp bolts (1301 and 1372 cc Turbo ie) . . . . . . . . . . . . . . 25 18
Anti-roll bar end fixing nuts (1301 and 1372 cc Turbo ie) . . . . . . . . . . . 15 11
13•16 Supplement: Revisions and information on later models

Starter motor brushes
(later models) - renewal#
25When renewing the starter motor brushes
on later models, the old brushes will need to
be crushed (in a vice or with a hammer) and
their leads then soldered to the new brushes.
Fuses - later models
26The fuse arrangement is slightly different
on later models, but the circuits protected are
still identified by a symbol. Refer to the
Specifications Section for full details. Note
also the terminal block with plastic cover,
which can be used to isolate the battery from
the electrical system by disconnecting the
leads from the terminals (photos).
Relays (Turbo ie models) -
general
27On Turbo ie models, the relays mounted
in the fuse block are as shown in Fig. 13.103.
Additional relays are located as follows:
Headlamp relay - on lead under main fuse
blockFuel injection system main control relay -
adjacent to airflow meter
Headlamps later models
28The headlamp units fitted on later models
differ according to model, but the bulb and
unit replacement details are generally the
same as described for previous models in
Chapter 9. Note that the rubber cover can
only be fitted with the tab to the top as shown
(photo).
Headlamp beam adjusters for
load compensation - later
models
29Some later models are fitted with
headlamp beam adjusters which allowtemporary resetting to be made (such as
when the car is fully loaded). Access to these
adjusters is made by lifting the bonnet (photo).
30Turn the adjusters anti-clockwise to lower
the beam to the normal level or clockwise to
raise the beam (when the car is unloaded).
Repeat the procedure on the opposite
headlamp unit an equal amount.
31Other later models have separate
horizontal and vertical beam adjusters,
positioned as shown (photos). A load
compensating lever is attached to the
adjusters to enable temporary resetting of the
headlamp beams, without changing the
normal adjustment. Turn the lever to the
appropriate side (right or left) to make the
adjustment as required. The normal setting
Supplement: Revisions and information on later models 13•105
15.26B Battery lead terminal block on the
1301 cc Turbo ie model15.23B Starter motor and wiring
connections on the 1372 cc ie engine
15.31B Headlamp vertical beam alignment
adjuster screw on a 1372 cc ie model. Note
the load compensator lever which is set in
the “O” (normal load) setting position15.31A Headlamp horizontal beam
alignment adjuster screw on a 1372 cc ie
model
15.29 Headlamp beam adjuster on the
999 cc Turbo ie model15.28 Headlamp unit fitted to the 1372 cc ie
model
15.26A Fuse block on the 1301 cc Turbo ie
model
13
Fig. 13.103 Auxiliary fuses and relays on
1301 cc Turbo ie models (Sec 15)
1 Horn relay
2 Heated rear screen relay
3 Foglamps relay
4 Radiator fan relay
5 Electric windows relay
6 Foglamps fuse
7 Radiator fan second speed fuse
8 Fuel injector fan fuse
9 Electric windows fuse
10 Electric fuel pump fuse

Door closure sensor
117The sensor consists of a microswitch
within the lock. The switch actuates the
warning lamp according to whether the lock is
in the open or closed mode.
Check control system sensors -
testing
Brake fluid level sensor
118With the fluid level correct, switch on the
ignition and depress the centre of the
reservoir cap. If the sensor switches are
working correctly, then “FAULT” should be
indicated on the check panel.
Coolant level sensor
119With the coolant level in the expansion
tank correct, switch on the ignition and then
pull the wiring plug from the sensor. “FAULT”
should be indicated on the check panel. If it is
not, then it is the panel which is faulty.
120An ohmmeter should be used to check
for continuity, holding the float in both the full
and low level positions.
Engine oil level sensor
121With the oil level correct, disconnect the
wiring plug from the dipstick, and then bridge
the plug terminals (not dipstick side) with a 12
ohm resistor. Switch on the ignition.
122If the red light on the check panel goes
out, then the fault is due to the sensor.
123If the light stays on, then it is the check
panel module which is faulty.
Door closure sensor
124Any fault in the lock microswitch can best
be detected using an ohmmeter.
16 Suspension
Front anti-roll bar -
removal and refittingª
1A front anti-roll bar is fitted to the 1301 cc,
1372 cc ie and 1372 cc Turbo ie engined
models. Removal of the bar on all models isas follows. Firstly loosen off the front
roadwheel bolts, then raise the front of the
car, securely support it on axle stands and
remove the front roadwheels.
2Disconnect the two gearchange rods from
the transmission.
3Unbolt and disconnect the anti-roll bar
insulating clamps from the floorpan (photo).
4Unbolt the end links from the track control
arms and withdraw the anti-roll bar (photo).
5Refitting is a reversal of removal, but only
tighten the nuts and bolts to the specified
torque with the car parked on level ground,
with four passengers and 40 kg of luggage
inside.
Suspension strut - later models
6The suspension strut upper mounting nuts
on later models also secure the brackets for
the mounting of ancillary components such as
the fuel filter, fuel system relays and fuses,
etc. (depending on model).
7When removing the suspension strut units,
it will therefore be necessary to detach and
support these brackets and their fittings
(photo).
17 Bodywork
Plastic components
1With the use of more and more plastic
body components by the vehicle
manufacturers (e.g. bumpers, spoilers, and in
some cases major body panels), rectification
of more serious damage to such items has
become a matter of either entrusting repair
work to a specialist in this field, or renewing
complete components. Repair of such
damage by the DIY owner is not really
feasible owing to the cost of the equipment
and materials required for effecting such
repairs. The basic technique involves making
a groove along the line of the crack in the
plastic using a rotary burr in a power drill. The
damaged part is then welded back togetherby using a hot air gun to heat up and fuse a
plastic filler rod into the groove. Any excess
plastic is then removed and the area rubbed
down to a smooth finish. It is important that a
filler rod of the correct plastic is used, as
body components can be made of a variety
of different types (e.g. polycarbonate, ABS,
polypropylene). Damage of a less serious
nature (abrasions, minor cracks, etc.) can be
repaired by the DIY owner using a two-part
epoxy filler repair material. Once mixed in
equal proportions, this is used in similar
fashion to the bodywork filler used on metal
panels. The filler is usually cured in twenty to
thirty minutes, ready for sanding and
painting.
2If the owner is renewing a complete
component himself, or if he has repaired it
with epoxy filler, he will be left with the
problem of finding a suitable paint for
finishing which is compatible with the type of
plastic used. At one time the use of a
universal paint was not possible owing to the
complex range of plastics encountered in
body component applications. Standard
paints, generally speaking, will not bond to
plastic or rubber satisfactorily. However, it is
now possible to obtain a plastic body parts
finishing kit which consists of a pre-primer
treatment, a primer and coloured top coat.
Full instructions are normally supplied with a
kit, but basically the method of use is to first
apply the pre-primer to the component
concerned and allow it to dry for up to
30 minutes. Then the primer is applied and
left to dry for about an hour before finally
applying the special coloured top coat. The
result is a correctly coloured component
where the paint will flex with the plastic or
rubber, a property that standard paint does
not normally possess.
Rear view mirrors Á
Interior
3The mirror is of safety type, “breaking” off
its ball fixing upon impact from a front seat
occupant.
4To remove the mirror, grip the head and
Supplement: Revisions and information on later models 13•111
16.7 Suspension strut upper mounting
nuts, showing bracket and cable clip on
the 1372 cc ie model16.4 Anti-roll bar fixing nuts (arrowed)16.3 Anti-roll bar clamp
13

14•20 Wiring diagrams
Component key for wiring diagrams 30 to 52
Note: Not all the items listed will be fitted to all models
No Description
1 Injector cooling fan
2 Left front light cluster
3 Left foglamp
4 Left front engine compartment earth
5 Radiator cooling fan
6 Double contact thermostatic switch
on engine radiator
6A Thermostatic switch on engine
radiator
7 Left horn
8 Right horn
9 Resistor for engaging radiator fan 1st
speed
10 Right front light cluster
11 Right foglamp
12 Right front engine compartment earth
13 Battery
14 Ignition coil
15 Ignition distributor with magnetic
impulse generator
16 Left front side direction indicator
17 Ignition power module
18 MPi electronic injection control unit
19 Join between injection/ignition cables
in engine compartment
20 Battery cables join in engine
compartment
21 Antiskid braking system wiring join
22 Starting go-ahead relay
23 Earth for battery
24 Radiator coolant temperature sender
unit for electronic injection
25 Anti-knock sensor
26 Injection system diagnostic socket
27 Switch signalling insufficient engine
oil pressure
28 Radiator coolant temperature sender
unit
29 Engine oil temperature sender unit
30 Engine oil pressure sender unit
31 Right front side direction indicator
32 Engine oil temperature sender unit
cable join
33 Battery recharging signal cable join
34 Windscreen washer pump
35 Rear screen washer pump
36 Reversing switch
37 Fuel injectors relay feed
38 Insufficient brake fluid level sensor
39 Left brake pad wear sensor
40 Microplex electronic ignition control
unit
41 Injection cables join in engine
compartment
42 Ignition cables join in engine
compartment
43 Join between battery cable and
injection cables
44 Join between engine cable and
battery cables
45 Left front brake pad cables join
46 Starter motorNo Description
47 Windscreen wiper motor
48 Headlamp washer pump
49 Fuel injector
50 Fuel injector
51 Fuel injector
52 Fuel injector
53 Supplementary air valve
54 Spark plug
55 Spark plug
56 Spark plug
57 Spark plug
58 Excess supercharging pressure
switch
59 Throttle position switch
60 Engine speed sensor
61 Ignition diagnostic socket
62 Connector block
63 Connector block
64 Alternator
65 Thermostatic switch for injector
cooling fan
66 Right brake pad wear sensor
67 TDC sensor
68 Connector block
69 Connector block
70 Connector block
71 Connector block
72 Join with right brake pad cables
73 Electronic earth
74 Power earth
75 Brake stop-lamp switch
76 20 A fuse for central locking
77 10 A fuse for electric fuel pump
78 30 A fuse for radiator cooling fan
79 30 A fuse for electric windows
80 10 A fuse for injector cooling fan
81 20 A fuse for headlamp
wash/wipe
82 20 A fuse for foglamps
83 Junction box with fuses and relays:
E1 Horn relay (for single tone horns
bridge between 86 and 87)
E2 Heated rear screen relay
E3 Heater (bridge between 85 and 30)
84 Join between front cable and rear
cables
85 Join between front cable and door
ajar sensor cables
86 Earth on dashboard, left hand side
87 Earth on dashboard, right hand
side
88 Choke warning light switch
89 Ignition switch
90 Hazard warning lights switch
91 Steering column switch unit
A Rear screen wash/wipe switch
B Horn button
C Direction indicators switch
D Windscreen wiper intermittent
speed selector switch
E Windscreen/headlamp washer
control switchNo Description
F Rear foglamps/headlamp washer
intermittent device switch
G Headlamp dip switch
H External lights switch
I Flasher switch
92 Foglamp relay
93 Electric fuel pump relay
94 Electric windows relay feed
95 Headlamp wash/wipe intermittent
device
96 Direction indicators/hazard warning
lights flasher unit
97 Central locking receiver
98 Central locking control unit
99 Join with brake pad cables
100 Join between engine cable and
dashboard cables
101 Automatic heater cable join
102 Instrument panel
A Foglamps warning light
B Main beam headlamps warning
light
C Side lights warning light
D Rear foglamps warning light
E Heated rear screen warning light
F Hazard warning lights warning
light
G Direction indicators warning light
H Handbrake applied and insufficient
brake fluid level warning light
I Choke warning light
K Instrument panel light bulbs
L Battery recharging warning light
M Insufficient engine oil pressure
warning light
O Antiskid braking system failure
warning light
P Maximum turbocharging pressure
warning light
Q Brake pad wear warning light
R Door ajar warning light
U Fuel level gauge
V Engine oil pressure gauge
W Engine oil temperature gauge
Y Tachometer
Z Coolant temperature gauge
103 Join with remote control central
locking cables
104 Cigar lighter
105 Radio receiver
106 Heater unit
107 Switch unit
A Heated rear screen switch
B Rear foglamps switch
C Switch unit light bulb
D Rear screen wiper switch
E Foglamps switch
F Clock
108 Left front electric window motor
109 Left front central locking geared
motor
110 Switch signalling left front door ajar

Fault FindingREF•9
REF
Introduction
The vehicle owner who does his or her own
maintenance according to the recommended
schedules should not have to use this section
of the manual very often. Modern component
reliability is such that, provided those items
subject to wear or deterioration are inspected
or renewed at the specified intervals, sudden
failure is comparatively rare. Faults do not
usually just happen as a result of sudden
failure, but develop over a period of time.
Major mechanical failures in particular are
usually preceded by characteristic symptoms
over hundreds or even thousands of miles.
Those components which do occasionally fail
without warning are often small and easily
carried in the vehicle.
With any fault finding, the first step is to
decide where to begin investigations.
Sometimes this is obvious, but on other
occasions a little detective work will be
necessary. The owner who makes half a
dozen haphazard adjustments or
replacements may be successful in curing a
fault (or its symptoms), but he will be none the
wiser if the fault recurs and he may well have
spent more time and money than was
necessary. A calm and logical approach will
be found to be more satisfactory in the long
run. Always take into account any warning
signs or abnormalities that may have been
noticed in the period preceding the fault –
power loss, high or low gauge readings,
unusual noises or smells, etc – and remember
that failure of components such as fuses or
spark plugs may only be pointers to some
underlying fault.
The pages which follow here are intended
to help in cases of failure to start or
breakdown on the road. There is also a Fault
Diagnosis Section at the end of each Chapter
which should be consulted if the preliminary
checks prove unfruitful. Whatever the fault,
certain basic principles apply. These are as
follows:Verify the fault. This is simply a matter of
being sure that you know what the symptoms
are before starting work. This is particularly
important if you are investigating a fault for
someone else who may not have described it
very accurately.
Don’t overlook the obvious. For example,
if the vehicle won’t start, is there petrol in the
tank? (Don’t take anyone else’s word on this
particular point, and don’t trust the fuel gauge
either!) If an electrical fault is indicated, look
for loose or broken wires before digging out
the test gear.
Cure the disease, not the symptom.
Substituting a flat battery with a fully charged
one will get you off the hard shoulder, but if
the underlying cause is not attended to,the
new battery will go the same way. Similarly,
changing oil-fouled spark plugs for a new set
will get you moving again, but remember that
the reason for the fouling (if it wasn’t simply an
incorrect grade of plug) will have to be
established and corrected.
Don’t take anything for granted.
Particularly, don’t forget that a ‘new’
component may itself be defective (especially
if it’s been rattling round in the boot for
months), and don’t leave components out of a
fault diagnosis sequence just because they
are new or recently fitted. When you do finally
diagnose a difficult fault, you’ll probably
realise that all the evidence was there from
the start.
Electrical faults
Electrical faults can be more puzzling than
straightforward mechanical failures, but they
are no less susceptible to logical analysis if
the basic principles of operation are
understood. Vehicle electrical wiring exists in
extremely unfavourable conditions – heat,
vibration and chemical attack and the first
things to look for are loose or corroded
connections and broken or chafed wires,especially where the wires pass through holes
in the bodywork or are subject to vibration.
All metal-bodied vehicles in current
production have one pole of the battery
‘earthed’, ie connected to the vehicle
bodywork, and in nearly all modern vehicles it
is the negative (–) terminal. The various
electrical components – motors, bulb holders,
etc – are also connected to earth, either by
means of a lead or directly by their mountings.
Electric current flows through the component
and then back to the battery via the
bodywork. If the component mounting is
loose or corroded, or if a good path back to
the battery is not available, the circuit will be
incomplete and malfunction will result. The
engine and/or gearbox are also earthed by
means of flexible metal straps to the body or
subframe; if these straps are loose or missing,
starter motor, generator and ignition trouble
may result.
Assuming the earth return to be
satisfactory, electrical faults will be due either
to component malfunction or to defects in the
current supply. Individual components are
dealt with in Chapter 9. If supply wires are
broken or cracked internally this results in an
open-circuit, and the easiest way to check for
this is to bypass the suspect wire temporarily
with a length of wire having a crocodile clip or
suitable connector at each end. Alternatively,
a 12V test lamp can be used to verify the
presence of supply voltage at various points
along the wire and the break can be thus
isolated.
If a bare portion of a live wire touches the
bodywork or other earthed metal part, the
electricity will take the low-resistance path
thus formed back to the battery: this is known
as a short-circuit. Hopefully a short-circuit will
blow a fuse, but otherwise it may cause
burning of the insulation (and possibly further
short-circuits) or even a fire. This is why it is
inadvisable to bypass persistently blowing
fuses with silver foil or wire.

Engine fails to turn when starter
operated
m mFlat battery (recharge use jump leads or
push start)
m mBattery terminals loose or corroded
m mBattery earth to body defective
m mEngine earth strap loose or broken
m mStarter motor (or solenoid) wiring loose or
broken
m mIgnition/starter switch faulty
m mMajor mechanical failure (seizure)
m mStarter or solenoid internal fault (see
Chapter 12)
Starter motor turns engine slowly
m mPartially discharged battery (recharge, use
jump leads, or push start)
m mBattery terminals loose or corroded
m mBattery earth to body defective
m mEngine earth strap loose m mStarter motor (or solenoid) wiring loose
m mStarter motor internal fault (see Chapter 9)
Starter motor spins without
turning engine
m mFlywheel gear teeth damaged or worn
m mStarter motor mounting bolts loose
Engine turns normally but fails to
start
m mDamp or dirty HT leads and distributor cap
(crank engine and check for spark)
m mNo fuel in tank (check for delivery at
carburettor) m mExcessive choke (hot engine) or insufficient
choke (cold engine)
m mFouled or incorrectly gapped spark plugs
(remove, clean and regap)
m mOther ignition system fault (see Chapter 4)
m mOther fuel system fault (see Chapter 3)
m mPoor compression (see Chapter 1)
m mMajor mechanical failure (eg camshaft drive)
Engine fires but will not run
m
mInsufficient choke (cold engine)
m mAir leaks at carburettor or inlet manifold
m mFuel starvation (see Chapter 3)
m mIgnition fault (see Chapter 4)
Engine will not start
REF•10Fault Finding
Spares and tool kit
Most vehicles are supplied only with
sufficient tools for wheel changing; the
Maintenance and minor repairtool kit detailed
in Tools and working facilities,with the
addition of a hammer, is probably sufficient
for those repairs that most motorists would
consider attempting at the roadside. In
addition a few items which can be fitted
without too much trouble in the event of a
breakdown should be carried. Experience and
available space will modify the list below, but
the following may save having to call on
professional assistance:
m mSpark plugs, clean and correctly gapped
m mHT lead and plug cap – long enough to
reach the plug furthest from the distributor
m mDistributor rotor, condenser and contact
breaker points (where applicable)m mDrivebelt(s) — emergency type may
suffice
m mSpare fuses
m mSet of principal light bulbs
m mTin of radiator sealer and hose bandage
m mExhaust bandage
m mRoll of insulating tape
m mLength of soft iron wire
m mLength of electrical flex
m mTorch or inspection lamp (can double as
test lamp)
m mBattery jump leads
m mTow-rope
m mIgnition waterproofing aerosol
m mLitre of engine oil
m mSealed can of hydraulic fluid
m mEmergency windscreen
m mWormdrive clips
m mTube of filler pasteIf spare fuel is carried, a can designed for
the purpose should be used to minimise risks
of leakage and collision damage. A first aid kit
and a warning triangle, whilst not at present
compulsory in the UK, are obviously sensible
items to carry in addition to the above. When
touring abroad it may be advisable to carry
additional spares which, even if you cannot fit
them yourself, could save having to wait while
parts are obtained. The items below may be
worth considering:
m mClutch and throttle cables
m mCylinder head gasket
m mAlternator brushes
m mTyre valve core
One of the motoring organisations will be
able to advise on availability of fuel, etc, in
foreign countries.
A simple test lamp is useful for checking
electrical faultsCarrying a few spares may save you a long walk!

F
Facia - 12•10, 13•107
Fan -2•3, 13•57, 13•71, 13•84
Fast idle adjustment -3•7, 3•9, 3•10, 3•11,
13•64
Fault finding- REF`•9et seq
Fault finding - braking system -8•9
Fault finding - clutch -5•3
Fault finding - cooling and heating systems
-2•8
Fault finding - driveshafts and hubs -7•6
Fault finding - Econometer -9•12
Fault finding - electrical system -9•14,
REF•9
Fault finding - engine -1•35, 1•36, 2•8,
3•13, 4•9, 13•92, REF•10, REF•11
Fault finding - fuel system -3•9, 3•13,
13•84
Fault finding - ignition system -4•9,
REF•11
Fault finding - Microplex ignition system -
13•92
Fault finding - steering - 10•4
Fault finding - suspension - 11•6
Fault finding - transmission -6•4
Fault finding - turbocharger system - 13•84
Filling - 12•3
Final drive output shafts - 13•94
Fire -0•5
Float adjustment -3•7, 3•8, 3•10, 3•11,
13•64, 13•66
Flywheel -1•19, 1•21, 1•31, 13•46, 13•53
Fog lamps - 13•106
Fuel evaporation control system - 13•78
Fuel filter - 13•67, 13•72, 13•74, 13•79
Fuel gauge fault -9•14
Fuel injection electronic control unit (ECU)
- 13•77
Fuel injection system - 13•68, 13•69
Fuel injection system fault finding - 13•84
Fuel injectors - 13•69, 13•70, 13•71, 13•76,
13•77, 13•81, 13•84
Fuel level transmitter -3•5
Fuel pressure regulator - 13•70
Fuel pump -3•5, 13•61, 13•69, 13•72,
13•76, 13•80, 13•81
Fuel rail - 13•70, 13•81
Fuel system-3•1et seq, 13•60, REF•4
Fuel system fault finding -3•9, 3•13
Fuel tank -3•5, 13•61, 13•72
Fume or gas intoxication -0•5
Fuses -9•5, 13•105
G
Gaiters -7•2, 10•2, 13•98
Gashes in bodywork - 12•2
Gaskets -1•20
Gearbox - SeeTransmission
Gearchange lever -6•2
Gearchange linkage - 13•94, 13•95
Glossary of technical terms- REF•13et seq
Grille - 12•3, 13•113
H
Handbrake -8•8, 8•9, REF•1
Handles - 12•11
HC emissions - REF•4
Headlamp -9•6, 9•7, 13•105, 13•106
Heated tailgate window -9•10
Heater -2•5, 2•6, 13•58, 13•59, 13•108
Heater fault -2•8
Horn -9•6, 13•106
Horn fault -9•14
HT leads - 13•92
Hubs -7•3, 7•4, 11•3
Hydraulic hoses and pipes -8•6
Hydraulic system -8•7
Hydrofluoric acid -0•5
I
Idle speed adjustment -3•7, 13•62, 13•65,
13•68, 13•75, 13•79
Idling fault -1•36, 3•13, 13•84
Ignition coil - 13•86, 13•90, 13•91
Ignition switch -4•8
Ignition system-4•1et seq, 13•85
Ignition system fault finding -4•9, 9•14,
REF•11
Ignition unit - 13•89
Indicators -9•7
Injectors - 13•69, 13•70, 13•71, 13•76,
13•77, 13•81, 13•84
Inlet manifold - 13•70, 13•77, 13•80
Instrument panel -9•8, 13•107
Intercooler - 13•84
Interior lamps -9•5, 9•8
Introduction to the Fiat Uno -0•4
J
Jacking -0•8
Joint mating faces and gaskets - REF•8
Jump starting -0•7
L
Lambda sensor - 13•82
Lamps -9•6, 9•7, 9•8
Leaks -0•9, 1•36, 13•84
LED (light emitter diode) -9•12
Lights fault -9•14
Locknuts,locktabs and washers - REF•8
Locks -9•11, 10•4, 12•4, 12•6, 12•7,
13•109
Loudspeakers -9•11
Lubricants and fluids -0•13
M
Magnetic impulse generator winding -
13•86
Main bearings -1•20, 1•30, 13•52
Maintenance -0•10, 13•18
Manifolds -3•12, 13•70, 13•77, 13•80
Master cylinder -8•5, 13•103, 13•93
Microplex ignition system - 13•86, 13•89Microplex ignition system fault finding -
13•92
Mirrors - 12•11, 13•111, REF•1
Misfire -1•35, 4•9, REF•11
Mixture adjustment -3•7, 13•62, 13•65,
13•68, 13•75, 13•79
MOT test checks- REF•1et seq
Mountings -1•13, 1•27, 13•26, 13•35,
13•49
N
Needle valve - 13•66
Number plate lamp -9•7
O
Oil cooler - 13•36
Oil filter -1•8
Oil level sensor - 13•110, 13•111
Oil pressure fault -1•36, REF•11
Oil pump -1•13, 1•19, 1•22, 1•26, 1•29,
13•24, 13•30, 13•35, 13•46, 13•53
Oil seals -1•20, 13•41, 13•44, 13•45,
13•94, REF•8
Oil,engine -0•6, 0•13, 1•3, 1•4, 1•8
Oil,transmission -0•6, 0•13, 6•1, 13•14,
13•95
Overheating -2•8, 4•9, REF•11
P
Pad wear sensor - 13•110
Pads -8•2, 13•100, 13•101
Parking lamp -9•7
Pedals -5•2, 8•9, 13•92, 13•102
Pinking -1•36, 13•84, REF•11
Pistons -1•12, 1•18, 1•22, 1•26, 1•30,
13•25, 13•26, 13•30, 13•35, 13•47,
13•48, 13•53
Plastic components - 13•111
Points -4•2, 4•3
Poisonous or irritant substances -0•5
Power module - 13•90
Pre-ignition -1•36, 13•84, REF•11
Pressure regulating valve -8•6, 13•102
Pressure sensor - 13•86
R
Radiator -2•3, 12•3, 13•57, 13•113
Radio -9•10, 13•110
Rear lamp cluster -9•7
Regulator (voltage) -9•4
Regulator (window) - 12•7
Relays -9•5, 13•71, 13•105
Repair procedures - REF•8
Respraying - 12•3
Rocker cover - 13•19
Rockers -1•19
Roof rack - 12•11
Routine maintenance -0•10, 13•18
Rust holes in bodywork - 12•2
REF•18Index