1957 FIAT 500 bulb

CHAPTER 11
THE ELECTRICAL EQUIPMENT
11:1 Description
11:2 Battery
11:3 The generator
11:4 The starter
11:5 The control box
1 1 : 6 Fuses
1 1 : 7 Flasher unit
11:1 Description
All models covered by this manual have 12 volts
electrical systems in which the negative battery terminal
is earthed. There are three units in the regulator box to
control the charging circuit; a cut-out, a current regulator
and a voltage regulator. These are adjustable but it must
be stressed that accurate moving coil meters are required
when checking or altering the settings. Cheap and
unreliable instruments will make accurate adjustments
impossible.
There are wiring diagrams in Technical Data at the end
of this manual to enable those with electrical experience
to trace and correct wiring faults.
For t h e U.K. Market the headlamps are of the double
filament dipping renewable bulb type with adjustments
for individual beam settings.
The battery is located in the front compartment
forward of the petrol tank and the fuses to the rear o f the
petrol tank.
Detailed instructions for servicing the electrical equip-
ment will be found in this chapter, but it must be pointed
out that it is not sensible to try to repair that which is
seriously defective, electrically or mechanically. Such
equipment should be replaced by new units which can
be obtained on an exchange basis.
F500111
11 :8 Windscreen wipers
1 1 : 9 The lighting system
11:10 Panel and warning lights
11:11 The horn
11:12 Lighting and flasher switch
1 1 : 1 3 Fault diagnosis
11.2 The battery
This of the 12-volt lead/acid type and has to meet
heavy demands for current particularly in the winter. To
maintain the performance of the battery at its maximum
it is essential to carry out the following operations.
Keep the top of the battery and surrounding parts dry
and clean, as dampness can cause leakage between the
securing clamps and the battery terminals. Clean off any
corrosion from the metal parts of the battery mounting
with diluted ammonia and paint them with an anti-
sulphuric paint. If the terminal posts are corroded,
remove the cables and clean w i t h diluted ammonia.
Smear the posts w i t h petroleum jelly before remaking the
connections and fit the terminals securely. High electrical
resistance due to corrosion at the terminal posts is often
responsible for lack of sufficient current to operate the
starter motor.
Ensure t h a t the filler plugs are in good condition and
show no signs of cracks. This may cause leakage of
electrolyte and consequent corrosion. Test the condition
of the cells after topping-up the electrolyte level with
distilled water to just above the tops of the separators as
shown in FIG 11 :2 . Never add neat acid. If it is
necessary to make a new electrolyte due to loss by
spillage add sulphuric acid to the
distilled water.
It is highly dangerous to add water to acid.

switch contacts. The starter motor rotates driving the
engine through the pinion and ring gear. As soon as the
engine fires the starter hand lever must be released which
will open the starter switch contacts so stopping the
starter motor and the pinion will return under the action
of a spring to a neutral position.
Tests for a starter which does not operate:
Check the condition of the battery and particularly
the connections to the terminals and to earth. If the
battery is charged, switch on the lights and operate the
starter hand lever control. If the lights go dim but the
starter does not operate it shows that current is reaching
the starter motor. The probability is that the pinion of the
starter shaft is jammed in mesh due to dirty pinion splines
or a broken spring. To release the pinion engage a low
gear with the ignition switched off and rock the vehicle
backwards and forwards which should allow the pinion
to be disengaged from the flywheel ring gear. If it proves
impossible to free a jammed pinion the starter motor must
be removed for examination and repair.
If the lamps do not go dim, check the starter switch and
also check the connection between the battery and the
starter switch to ensure that they are tight and making
good electrical connection. If the starter motor still does
not work it should be removed from the power unit for
inspection.
Removing the starter:
To remove the starter motor from the power unit
proceed as follows:
1 Disconnect the positive terminal from the
battery post.
2 Release the hand lever control cable from the starter
motor engagement lever.
3 Disconnect the battery cable terminal from the starter
motor switch.
4 Remove the retaining nuts and washers holding the
starter motor to body to the transmission bellhousing
and gently ease backwards and lift away the starter
motor.
Examining the commutator and brush gear :
Refer to FIG 11:5 and remove the coverband 5. Hold
back each spring in turn and pull gently on the flexible
connection to the brush. If the brush does not move
freely remove it from its holder and polish the sides using
a fine file. Mark the brushes so that they will be replaced
in their original positions. If the brushes are so worn that
they no longer bear onto the commutator, or the brush
connector has become exposed on the running face, the
brushes must be renewed.
If the commutator is blackened it should be cleaned by
turning it against a petrol-moistened cloth. With the
brushes and commutator overhauled hold the body of the
starter motor in a vice and connect it with thick cables to a
12 volt battery. One cable should go to the starter
switch terminal and the other to the body of the starter.
The starter should run at high speed. If it does not, it
must be dismantled for further examination and testing.
F500115 Dismantling the starter:
To dismantle the starter proceed as follows:
1 Remove the coverband 5 (see FIG 11:5) and hold
back the brush springs and take out the brushes.
2 Remove the starter switch by releasing the t w o
mounting screws and lift away the switch.
3 Remove the commutator end head 16, slide off the
armature assembly from the drive unit and from the
pole shoes.
4 Release the engagement lever pin 6 and spring 7 from
the lever operating bracket on the drive end head. Lift
away the lever and withdraw the pinion assembly
complete which is shown in FIG 11:5.
Servicing the brushes
Test the brush springs with a balance, the correct
tension is 2.5 to 2.9 Ib. according to the wear of the
brushes. Fit a new spring if the tension is low.
The life of the brushes depends on the type of service
in which the vehicle is being used. In normal circum-
stances even when the starter is being used frequently,
the brushes should last more than 18,000 miles. If the
wear is found to be abnormal it will probably be found
that the commutator is either damaged or excessively
w o r n . Only Fiat replacement brushes must be used.
Testing the field coils:
Use a 12 volt bulb in one lead of a 12 volt battery.
Connect one lead to the brush connection joint to the coil
field and the other to the field coil current supply lead.
If the bulb does not light there is a break in the f i e l d coil
windings. This is not a complete test as it is still possible
for a coil to be earthed. Check this by moving the lead
from the brush connection and holding it on a clean
metal
surface on the yoke or body. If the bulb lights it shows
that the field coils are earthed.
The only sure way of curing faulty field coils is to take
the starter motor to a service station.
Examining the armature:
The armature shaft may be bent due to the starter
being operated whilst the engine is operating. Do not try
to straighten a bent shaft or machine the armature core to
obtain the correct clearance.
If the commutator is damaged or any wires or segments
have lifted from it, the assembly will have to be renewed.
Starter bearings:
Bearing bushes are of the porous bronzed type and
must not be reamed after fitting. Worn bearings should
be withdrawn by screwing a tap into them and pulling
on the tap. New bushes must be immersed in engine oil
for approximately twenty four hours before fitting. Press
them into place using a suitably sized drift which has a
spigot the length of the bearing and the diameter of the
starter shaft. When this is withdrawn after fitting, the
bore of the bush should be correct to size.
The pinion drive:
This unit is shown in FIG 11:5. The chief sources of
trouble are a dirty unit or a broken starting engagement

4
53 2 1
7
6
FIG 11 :6 Regulator assembly GN 1.12.16
Key to Fig 11:6 1 Voltage regulator adjusting spring
2 Current regulator adjusting spring 3 Cutout adjusting
spring 4 Voltage regulator adjustment arm 5 Current
regulator adjustment arm 6 Cutout adjustment blade spring
7 Soldering of cutout shunt and series winding
FIG 11:7 Wiring diagram for checking the cutout
closing voltage
Key to Fig 1 1 : 7 GR Regulator GN 1.12.16 G Generator
FIAT DSV 90.12.1 6.3 S V Voltmeter, 20 V scale (0.5%
accuracy) L 12 V, 3 to 5 W bulb
FIG 11:8 Wiring diagram for checking the reverse
current of cutout
Key to Fig 11:8 GR Regulator GN 1.1 2.1 6 G Generator
FIAT DSV 90.1 2.1 6.3 S B Battery, 50 Ah, fully charged
A Ammeter, asymmetrical scale 10-0-15 A V Voltmeter,
20 V scale (0.5% accuracy)
116spring 13. Should any defect be found then the pinion
assembly must be renewed as one complete unit. After
examining to ensure that there are no defects thoroughly
clean using petrol.
Reassembling and refitting the starter:
In both cases this is a simple reversal of the dismantling
procedure. Grease t h e drive splines and the engagement
lever groove in the sleeve.
11:5 The control box:
Description:
The generator regulator fitted to the new 500 model
consists of three separate
units; voltage regulator,
current regulator, cut-out relay (see FIG 11 :6).
The voltage regulator and current regulator relays
comprise a U-shaped body one of whose arms is bent
to form a flange, whilst the other adjustment arm pro-
vides a stop for the hinge spring. The U-shaped body is
secured to the frame by the core threaded shank and
carries, on the flanged end, an armature supported by a
hinge spring which comprises a steel leaf and bi-metal
leaf overimposed in the current regulator and bi-metal
leaf in the voltage regulator. The armature carries the
movable contact.
Fixed contacts of both voltage and current regulators
are mounted on t w o blade springs which are secured to a
single bracket rivetted to the U-shaped adjustment arm.
The design of the t w o fixed contacts carrier blade springs
is such as to permit the adjustment of the contact
position by suitably bending the blade springs. The cut-
out is similar in design to the other two relays as shown
in FIG 11:6. Again the hinge spring is bi-metallic as in
the voltage regulator.
All the armatures are provided w i t h blade springs, so
that the tension may be adjusted to the required setting
value. This adjustment is obtained by bending the
adjustment arms.
The voltage regulator coil comprises a fine wire wind-
ing w i t h a great number of turns, shunt connected to the
generator.
The cut-out coil comprises a fine wire winding with a
great number of turns shunt connected to the generator,
and of a winding comprising a few turns of heavy gauge
wire, which is connected in series w i t h the generator
charge circuit (cut-out series winding).
The current regulator coil comprises a few turns of
heavy gauge wire which is series connected with the
generator charge circuit.
The generator regulator base has three terminals to
which the various cables are connected.
No. 51 — connection to generator positive terminal.
No. 67 — connection to generator field winding.
No. 30 — connection to electrical accessories.
The regulator cover is secured to the base w i t h a
rubber gasket placed in between which seals the unit
against the ingress of moisture or dust.
A regulation resistor is fitted under the base and is
secured to the voltage regulator and current regulator
relay core threaded shanks.

Checking cut-out:
1 Closing voltage:
This test should be carried out at a temperature of
25°±10°C and the regulator should be connected to a
generator test bed as shown in FIG 11:7. The unit should
be operated under no load conditions for between 15 -
18 minutes with the cover installed and w i t h a voltage of
between 16.5 volts for an initial operating temperature of
15-20°C or 15 volts for an initial operating temperature
of 20-35°C. This will enable thermal stabilization of the
unit to be obtained so that the temperature of both the
cut-out shunt windings and the bymetallic springs
increase due to the heat developed by the windings and
reaches the normal operating setting.
Once thermal stabilization has been obtained the
generator should be restarted and the speed gradually
increased so that immediately the test lamp starts to
glow the voltmeter reading may be taken. This will be
the value of the cut-out contact closing voltage.
2 Reverse current:
This check should be carried out at a temperature range
of between 25°±10°C and it is recommended that it is
performed as soon as possible after the closing voltage
test so that the thermal stabilization remains unaltered.
Connect the regulator as shown in FIG 11:8 and
gradually speed up the generator to 4500 rev/min for
approximately 5 minutes. Ensure that the voltmeter reads
at least 14.5 volts and then gradually reduce the generator
speed carefully watching the movement of the ammeter
needle which should at first indicate a charging current
and then gradually move to zero and then to the other side
of the scale to indicate reverse current value. If the
generator speed is reduced further the reverse current
reading will increase to a given value and then suddenly
fall to zero which will indicate that the cut-out contact
has opened. This limit indicates the maximum reverse
current value which should not, under any circumstances,
exceed 16 amps.
During this test, to obtain the maximum reverse
current possible the reduction in generator speed must
not take more than 10 seconds otherwise the battery
voltage will drop excessively.
Checking voltage regulator:
This test should be carried out w i t h the regulator under
half load and at a temperature of 50°± 3°C. Connect the
regulator as shown in FIG 11:9 and operate the regulator
for approximately 30 minutes by supplying a current half
that of regulated current which is 1 6 ±5 amp. Once the
regulator has been brought to the required temperature
stop the generator and start it again, gradually increasing
the speed to a maximum of 4500 rev/min. Adjust the
rheostat for a generator output corresponding to half load
current of 8 ± 2 amps. When this generator output has
been set the voltage should be 14.2± .3 volts.
Checking current regulator:
Leave the regulator connected as shown in
FIG 11 :10
and this test must be carried out immediately after testing
the half load regulated voltage of the voltage regulator
when connected to a battery. Check that the ammeter
fitted will accommodate a 40 amp deflection: if not a
F500117
FIG 11 :9 Wiring diagram for checking the current and
voltage regulators
Key to Fig 11:9 GR Regulator GN 1.1 2.1 6 G Generator
FIAT D 90.12.16.3 V Voltmeter, 20 V scale (0.5% accuracy)
A Ammeter, 20 A scale (to check voltage regulator) and 40 A
scale (to check current regulator)
B Battery, 50 Ah, fully chargedR Rheostat, 25 A. 3
FIG 11 :10 Wiring diagram for setting the cut-out relay
Key to Fig 11 :10 B 2 V battery B 20 V batteryA Ammeter, 20 A scale ( 1 % accuracy) V Voltmeter, 20 V
scale (0.5% accuracy), directly connected to terminals 31—51
P Potentiometer for voltage adjustment, having such a capacity
that the current draw of the cut-out shunt winding does not
cause sensible variations in the voltage readings (voltmeter
under no load) S Test lamp, with 2 V, 3 W bulb, to signal
opening and closing of contacts R Rheostat, 4 12
AR Voltage drop resistor, suitable to allow turning on of A withT open and cut-out contacts open
Setting of instruments before inserting the unit: P At
minimum (voltmeter reads zero) T Open R All inserted
(max. resistance) T Open
FIG 11:11 Wiring diagram for setting the voltage and
current regulators
Key to Fig 11 :11 GR Regulator assembly GN 1.12.16
G Generator D 90.12.16.3 V Voltmeter, 20 V scale (0.5%
accuracy) A Ammeter, 20 Amp. scale (for voltage regulator),
or 40 Amp. scale (for current regulator) R Rheostat, 25
Amps., 3 Ohms B 50 Amp/h battery, fully charged I Switch

Checking cut-out:
1 Closing voltage:
This test should be carried out at a temperature of
25°±10°C and the regulator should be connected to a
generator test bed as shown in FIG 11:7. The unit should
be operated under no load conditions for between 15 -
18 minutes with the cover installed and w i t h a voltage of
between 16.5 volts for an initial operating temperature of
15-20°C or 15 volts for an initial operating temperature
of 20-35°C. This will enable thermal stabilization of the
unit to be obtained so that the temperature of both the
cut-out shunt windings and the bymetallic springs
increase due to the heat developed by the windings and
reaches the normal operating setting.
Once thermal stabilization has been obtained the
generator should be restarted and the speed gradually
increased so that immediately the test lamp starts to
glow the voltmeter reading may be taken. This will be
the value of the cut-out contact closing voltage.
2 Reverse current:
This check should be carried out at a temperature range
of between 25°±10°C and it is recommended that it is
performed as soon as possible after the closing voltage
test so that the thermal stabilization remains unaltered.
Connect the regulator as shown in FIG 11:8 and
gradually speed up the generator to 4500 rev/min for
approximately 5 minutes. Ensure that the voltmeter reads
at least 14.5 volts and then gradually reduce the generator
speed carefully watching the movement of the ammeter
needle which should at first indicate a charging current
and then gradually move to zero and then to the other side
of the scale to indicate reverse current value. If the
generator speed is reduced further the reverse current
reading will increase to a given value and then suddenly
fall to zero which will indicate that the cut-out contact
has opened. This limit indicates the maximum reverse
current value which should not, under any circumstances,
exceed 16 amps.
During this test, to obtain the maximum reverse
current possible the reduction in generator speed must
not take more than 10 seconds otherwise the battery
voltage will drop excessively.
Checking voltage regulator:
This test should be carried out w i t h the regulator under
half load and at a temperature of 50°± 3°C. Connect the
regulator as shown in FIG 11:9 and operate the regulator
for approximately 30 minutes by supplying a current half
that of regulated current which is 1 6 ±5 amp. Once the
regulator has been brought to the required temperature
stop the generator and start it again, gradually increasing
the speed to a maximum of 4500 rev/min. Adjust the
rheostat for a generator output corresponding to half load
current of 8 ± 2 amps. When this generator output has
been set the voltage should be 14.2± .3 volts.
Checking current regulator:
Leave the regulator connected as shown in
FIG 11 :10
and this test must be carried out immediately after testing
the half load regulated voltage of the voltage regulator
when connected to a battery. Check that the ammeter
fitted will accommodate a 40 amp deflection: if not a
F500117
FIG 11 :9 Wiring diagram for checking the current and
voltage regulators
Key to Fig 11:9 GR Regulator GN 1.1 2.1 6 G Generator
FIAT D 90.12.16.3 V Voltmeter, 20 V scale (0.5% accuracy)
A Ammeter, 20 A scale (to check voltage regulator) and 40 A
scale (to check current regulator)
B Battery, 50 Ah, fully chargedR Rheostat, 25 A. 3
FIG 11 :10 Wiring diagram for setting the cut-out relay
Key to Fig 11 :10 B 2 V battery B 20 V batteryA Ammeter, 20 A scale ( 1 % accuracy) V Voltmeter, 20 V
scale (0.5% accuracy), directly connected to terminals 31—51
P Potentiometer for voltage adjustment, having such a capacity
that the current draw of the cut-out shunt winding does not
cause sensible variations in the voltage readings (voltmeter
under no load) S Test lamp, with 2 V, 3 W bulb, to signal
opening and closing of contacts R Rheostat, 4 12
AR Voltage drop resistor, suitable to allow turning on of A withT open and cut-out contacts open
Setting of instruments before inserting the unit: P At
minimum (voltmeter reads zero) T Open R All inserted
(max. resistance) T Open
FIG 11:11 Wiring diagram for setting the voltage and
current regulators
Key to Fig 11 :11 GR Regulator assembly GN 1.12.16
G Generator D 90.12.16.3 V Voltmeter, 20 V scale (0.5%
accuracy) A Ammeter, 20 Amp. scale (for voltage regulator),
or 40 Amp. scale (for current regulator) R Rheostat, 25
Amps., 3 Ohms B 50 Amp/h battery, fully charged I Switch

FIG 11:12 Wiring diagram for setting the cutout relay
Key to Fig 11 :12 B 2 V battery B 20 V battery
A Ammeter, 15 A scale ( 1 % accuracy) V Voltmeter, 20 V
scale (0.5% accuracy), directly connected to terminals 31-51
P Potentiometer for voltage adjustment, having such a capacity
that the current draw of the cutout shunt winding does not cause
sensible variations in the voltage readings (voltmeter under no
load) S Test lamp, with 2 V, 3 W bulb, to signal opening
and closing of contacts R Rheostat, 4 , 1 2 A R Voltagedrop rheostat, suitable to allow turning on of S with T open and
cutout contacts open
Setting of instruments before inserting the unit: P At
minimum (Voltmeter reads zero) T Open R All inserted
(max. resistance) T Open
1
2
3
4
5
6
FIG 11:13 Location of electrical system fuses
Key to Fig 11 :13 1 Fuse N o . 30.2 2 Fuse N o . 30.3
3 Fuse N o . 56.b1 4 Fuse N o . 56.b2 5 Fuse N o . 15.54
6 Fuse N o . 30
meter w i t h a fuller scale deflection of 40 amp must be
substituted. Adjust the rheostat to give maximum
resistance and operate the regulator for approximately
30 minutes with regulator controlled current and 13 volt
supply. The resistor R of the rheostat should be adjusted
until the current is steady whilst the voltage drops. This
will indicate that the unit has reached normal operating
temperature. Stop the generator, restart it and speed up
gradually to 4500 rev/min. Check that the regulated
current value corresponds to the specified value of
1 6± .5 amps. By continually reducing the resistance the
current should remain constant. The voltage however
should decrease to as l o w as 12 volts.
118
Cut-out relay adjustment:
Ascertain the type of regulator fitted and then wire to
the test unit as shown in FIG 11:10 or FIG 11 :12.
Before the unit is assembled to the test bed the instru-
ments should be set as follows:
P - at minimum so that voltmeter reads zero.
T — open.
R - all inserted giving maximum resistance.
T - open.
1 Contact closing voltage:
This test should be carried out at an ambient tempera-
ture of 25°±10°C. Close the switch T and stabilize the
regulator thermally by feeding current into it for approxi-
mately 15 to 18 minutes at 16.5 volts which is obtained
by adjusting P for initial regulator operating temperatures
of between 15°-20°C or at 15 volts for initial operating
temperatures of 20°-35°C. Once the stabilizing of the
regulator has been completed bring the voltage to 12 6±
.2 volts by adjusting P. Adjust the load on the setting
spring by bending the relevant arm until the pilot light S
is extinguished. Reset P to m inimum and again increase
the voltage by P and check that the pilot lamp is extin-
guished at the specified voltage.
2 Reverse current:
This test must be carried out at a temperature of
25°± 10°C and it is recommended that it is carried out as
soon as possible after the closing voltage test so as to
maintain minimum regulator thermal stability. With the
switch T closed bring the voltage to 14.5 volts by
operating P. The contacts of the cut-out should be closed
and the pilot lamp S off. Close T and increase the reverse
current by means of the rheostat R and check that the
pilot lamp S glows as the contacts part. The opening may
also be unsteady which will be indicated by a slight
buzz from the unit. Check the value of the ammeter of the
reverse current causing the opening of the contacts and
this should not exceed 16 amps. If the reading is unstable
or S lights up at the recommended limit reset the reverse
current to the minimum value and repeat the test once
more. Finally open the switches T and T and again
adjust rheostat R and P to the minimum settings.
Voltage regulator adjustment:
This test should be carried out at a temperature of
5 0 ° ±3 ° C . Connect the unit as shown in FIG 11 :11 and
load the voltage regulator adjusting springs by bending
the relevant arm. With the unit at the required test
temperature close 1 start the generator and stabilize
the regulator thermally by feeding a current for 30
minutes at 15 volts, which is obtained by adjusting the
generator speed. The generator should then be stopped,
I opened and the generator restarted and gradually
speeded up to 4500 rev/min. The voltage regulator
spring load adjustment should be set by suitably bending
the relevant adjusting arm and by rheostat R so as to have
a voltage of 14.2±.3 volts and a half load current of
8 ± 2 amps. Finally check the steadiness and accuracy
of the voltage regulator setting by stopping the generator
and restarting after approximately 2 minutes and gradually
speeding up to 4500 rev/min.

WINDSHIELD WIPER
MOTOR ASSY
WIPER MOTOR SCREWS
WIPER MOTOR BRACKET
FIG 11:15 Arrangement of windshield wiper unit on
vehicle
B M INT F
SC12 V
31
D
A
SWITCH PARKING
0 ON
SWITCH LEVER POSITIONS
FIG 11:16 Windshield wiper wiring diagram
Key to Fig 11 :16 A Series winding B Shunt winding
D Switch M Motor S Additional winding F INT
C =Terminals
120signal lamp pairs. The flasher unit connections are in
FIG 11:14 and the unit is of the hot wire type.
Faulty operation of flashers:
In cases of trouble check the bulb for broken filaments.
Refer to the wiring diagrams in Technical Data and check
all flasher circuit cables and connections. Check the
appropriate fuse. Switch on the ignition and check w i t h
a voltmeter between flasher unit positive terminal and
earth to see if battery voltage is present. Connect together
flasher unit positive terminal and L and operate the
direction indicator switch. If the flasher lamps now light,
the flasher unit is defective and must be renewed. It is not
possible to dismantle and repair a faulty flasher unit.
Before removing make a note of the connections so that
they will be replaced correctly when the new unit is being
installed.
Before making the connections it is advisable to check
the circuits to ensure that the new flasher unit is not
damaged by wrong connection. Test by joining the
cables normally connected to the unit and operate the
switch. If the connections are wrong the appropriate
fuse will blow but no damage will be done to the flasher
unit.
Never insert terminal L directly to earth without having
first connected in series the bulbs specified, otherwise
the flasher unit will be damaged. For the same reason
terminal L must never be shorted to ground nor must there
by any short circuits in any of the leads from the L
terminal to the bulbs. The flasher unit must never receive
blows of any kind since it is a very delicate component
and easily damaged.
11:8 Windscreen wipers
Description:
The windscreen wiper assembly comprises a motor
unit that drives t w o wiper blades through a reduction
gearing and mechanical linkage. The reduction gear
includes a worm screw on the motor armature shaft and a
helical pinion. The motor, left blade pivot and linkages
are mounted on a sheet metal bracket, whilst the right
blade pivot is connected to the main drive link. When
assembled to the vehicle the right blade pivot is fixed
directly onto the body. The unit is provided w i t h an
automatic parking device which ensures that the blades
return to their correct park position. The w
indscreen wiper
is- controlled by a lever switch with three separate
positions on earlier models or a simple on-off switch on
later models.
Maintenance:
Maintenance is confined to the changing of the wiper
blades when they have deteriorated and occasional
lubricating of the mechanical linkage.
Wiper unit faulty operation :
1 It is important that the wiper unit assembly is correctly
fitted to the body otherwise distortion of the wiper
mounting bracket can occur which will cause
abnormal stresses on the pivot and linkages resulting
in irregular and difficult blade sweep.
2 If the blades keep on sweeping at a reduced speed
although the switch lever has been pressed to the

parking position the trouble will be found in the sliding
sector which fails to open the switch D (see FIG
11 :16) . Check by removing the four motor cover
mounting screws and uncover the sliding sector. If
possible suitably bend the sector to bring it against
into contact with the rod tip of switch D.
3 If the automatic parking of the blades does not occur
when the switch lever is fully depressed to the parking
position but the motor stops when the switch is
operated the cause of the trouble is that the switch D
is not closing and consequently no current is flowing
between the terminals C and INT. This will probably
be due to dirt lodged between the movable contact
and the fixed contacts of switch D. Thoroughly wash
the components with petrol and if necessary reface
the contacts using a very fine file.
4 Should the motor unit be noisy in operation although
still operating reliably the noise is probably due to the
reduction gear operation, whereby the pinion and
worm are excessively worn or a tooth chipped. The
motor unit must be renewed as motor unit parts are
not available in service.
5 If the switch lever is pushed upwards to the 'on'
position or depressed downwards to the Parking
position and the wiper is still inoperative thoroughly
check all terminal connections for tightness and
cables for damage which if all appear to be correct the
failure of the wiper to operate indicates an internal
fault of the motor unit which
should be repaired or
renewed as necessary.
Removal and refitting the motor:
Remove the wiper arms and the electrical connections
to the motor. Dismantling is a straightforward operation
providing that as all items are removed so they are
inspected and a note made of their locations. However,
reassembly requires more care and the following
procedure should be adopted.
1 Mount the wiper unit onto the body by fully tightening
the nuts fixing the pivots onto which the arms are
fitted. Ensure t h a t the rubber sealing bushes between
the pivots and body are correctly assembled to prevent
water ingress. Slightly lubricate with glycerine.
2 Secure the mounting bracket lower edge to the body
by means of the special square bracket. It is important
not to distort the mounting bracket and ease of
assembly is ensured by elongated holes in the square
bracket. By suitable adjustment the linkages will not
be subjected to distortion or abnormal stresses during
operation.
3 Fit the motor unit to the mounting bracket tightening
the screws and reassemble the main link to the pivot
lever. Ensure t h a t the l o c k i n g of the fastener on the
pivot lever is secure so that it does not become loose
during operation.
4 Remake all the electrical connections and run the
motor for a short time whilst checking all the switch
positions including the automatic parking. It is at this
position that the wiper blades and arms are assembled
to the wiper mechanism.
5 Onto the pivots, install the shims, snap ring, wiper arm,
plain washer and lockwasher. Fully tighten the nuts
with the wiper arms in the parked position.
F500
FIG 11 :17 Headlamp removal
Key to Fig 11:17 1 Screw for vertical beam adjustment
2 Screw for horizontal beam adjustment 3 Headlamp
locating hook 4 Headlamp retaining ring and spring
5 Lamp unit 6 Bulb spring retainers 7 Bulb
8 Junction block
6 Ensure that the wiper arms can be tilted 100 deg.
downwards without striking against the cowl or front
compartment lid. Also ensure that the blade pressure
on the glass is 10.6 to 12.3 oz.
1 1 : 9 The lighting system
Description:
The lighting system comprises t w o headlights with
double filament bulbs of 45 watts for main beam and
40 watts for dip. Headlight control is operated through
the outer light switch below the steering wheel after the
toggle switch at the centre of the instrument panel has
been operated.
A double filament bulb for the front parking and
direction indicator lights is located below the headlights:
alternatively, the parking light may be incorporated in the
headlamp unit. The bulb is of 5 watt rating for the parking
lights and 20 watts for the direction indicator lights.
Two side direction indicator lamps are fitted with 2.5
w a t t b u l b s . The rear number plate is illuminated by a 5
watt bulb operated from the main lighting circuit.
Two three purpose rear light units are fitted and are
provided with a one single filament 20 watt bulb for the
direction indicator and one double filament bulb of 5 watt
rating for the parking circuit and 20 watt for stoplights.
Headlamp removal:
The headlamp on earlier cars may be removed from the
front panel by slightly depressing the lens and rotating the
unit counterclockwise through 15 deg. on later cars a
retaining spring is unhooked inside the front compart-
ment and the lamp can then be lifted out (FIG 11 :17).
121