1963 FIAT 500 lighting switch

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.

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).
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Before removing an apparently faulty horn check the
wiring and connections. Check that the mounting bolts
are tight and that the horn does not foul any adjacent part.
Removal and installation:
This is a straightforward operation and the only
precaution to be taken is to ensure that the rubber gasket
bonded to the horn body does not become detached. If
the horn is renewed, before installing the new horn bond
the rubber gasket to the new unit with adhesive in
the same position as was on the original horn unit fitted.
Should the horn fail to operate the following points
should be noted.
1 Damaged horn.
2 Broken connection between battery and horn.
3 Broken connection between horn and push button on
steering wheel
4 Damaged push button mechanism.
5 Directional signal and outer lighting changeover
switch blade contact failing to make contact with the
steering wheel hub ring contact.
6 Current lead displaced from the horn blade contact on
the directional signal and outer lighting switch.
7 Distorted or broken diaphragm in horn.
8 Connections or inner windings
broken or burnt.
9 Electro-magnet contact points dirty or excessively
worn.The contacts may be adjusted by the adjusting screw
after the points have been cleaned and refaced.
To adjust the tone of the horn use a ring spanner and
screwdriver as shown in FIG 11 :23.
It is recommended that if the horn unit operation is
unreliable a new unit should be fitted rather than the
original one repaired.
11:12 Lighting and flasher switch
Description:
The two switches provide a directional signal switch
which automatically returns to the rest position once a
turn has been negotiated and the steering wheel is
brought back to the straight-ahead position. The change
over switch controls the outer lights and the headlights
flasher. The complete unit is located under the steering
wheel on the steering column.
Switch unit removal:
1 Carefully pry off the horn push button at the steering
wheel centre using a fine blade screwdriver.
2 Disconnect the positive terminal of the battery.
3 Disconnect the plug in contact in the steering wheel
hub.
4 Unscrew the steering wheel retaining nut from the
inner column and remove the steering wheel from the
shaft.
5 Slacken the bolts securing the steering column support
to the body
6 Remove the plug in contacts from the switch unit
ensuring that their correct location is noted for re-
assembly.7 Remove the switch unit from the steering column.
124
Switch unit installation:
This is the reverse procedure to dismantling. It is
advisable after installation to check that the steering
wheel when in the straight-ahead position and the
directional signal switch lever in neutral, the reference
index on the outer face of the directional signal switch
drum is in line with the index on the steering wheel hub.
This will ensure correct sequence of operation.
11:13 Fault diagnosis
(a) Battery discharged
1 Lighting circuit shorted
2 Terminals loose or dirty
3 Generator not charging
4 Regulator or cut-out units not working properly
5 Battery internally defective
(b) Insufficient charging current
1 Loose or corroded battery terminals
2 Generator driving belt slipping
(c) Battery will not hold a charge
1 Low electrolyte level
2 Battery plates sulphated
3 Electrolyte leakage from cracked casing or top sealing
compound
4 Plate separators ineffective
(d) Battery overcharged
1 Voltage regulator needs adjusting
(e) Generator output low or nil
1 Belt broken or slipping
2 Regulator unit out of adjustment
3 Worn bearings, loose pole pieces
4 Commutator worn, burned or shorted
5 Armature shaft bent or worn
6 Insulation proud between commutator segments
7 Brushes sticking, springs weak or broken
8 Field coil wires shorted, broken or burned
( f ) Starter motor lacks power or will not operate
1 Battery discharged, loose cable connections
2 Starter pinion jammed in mesh with flywheel gear
3 Starter switch faulty
4 Brushes worn or sticking, heads detached or shorting
5 Commutator dirty or worn
6 Starter shaft bent
7 Engine abnormally stiff
(g) Starter motor inoperative
1 Check 1 in (f)
2 Armature or field coils faulty

(h) Starter motor rough or noisy
1 Mounting bolts loose
2 Damaged pinion or flywheel gear teeth
( i ) Lamps inoperative or erratic
1 Battery low, bulbs burned out
2 Faulty earthing of lamps or battery
3 Lighting switch faulty, loose or broken wiring
connections
F500
125
(j) Wiper motor sluggish, taking high current
1 Faulty armature
2 Bearings out of alignment
3 Commutator dirty or short-circuited
(k) Wiper motor operates but does not drive
arms
1 Gearbox components worn