1964 FIAT 500 ECU

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.

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

FIG 11:18 Replacement of bulb from inside f r o n tcompartment
Key to Fig 11 :18 1 Double-filament bulb 2 Bulbholder
3 Side direction indicator light 4 Bulbholder shield
PARKING LAMP
LENS
SIDE DIRECTIONINDICATOR
FIG 11 :19 Disassembling front parking and direction
indicator lamp
Replacement of the bulb is achieved from inside the front
compartment by pulling down the upper lug of the
rubber protection cap at the rear of t h e headlight unit and
freeing the bulb holder. Pull up the bulb holder to
reflector fastener spring and pull out the bulb holder
complete and replace the bulb as necessary.
Beam setting:
Accurate setting is best left to a service station
equipped with the necessary equipment. The main beams
must be set parallel to the road surface or in accordance
with local regulations. Adjustment is made by turning
the top screw 1 as indicated in FIG 11:17 for the
vertical setting and the lower screw 2 for the horizontal
setting.
122
FIG 11 : 20 Disassembling tail parking, stop, direction
indicator lamp and reflector lens REFLECTOR LENS PARKING A N D
STOP LAMP INDICATOR LAMP
DIRECTION
LENSLENS
SCREWS
Lamps light when switched on but gradually fade:
Check the battery as it is incapable of supplying
current for any length of time. Front parking and direction indicator lamp:
To replace the double filament bulb, release the screws
securing the lens to the lamp casing as shown in FIG
11 :19 and remove the bulb from its bayonet holder. Where
the parking lamp is in the headlamp unit the bulbholder
can be pulled out inside the front compartment.
Rear parking, direction indicator, stop lamps and
reflector lens:
To renew any of the t w o bulbs remove the t w o screws
securing the lens to the lamp casing as shown in FIG
11 : 2 0. Bulbs are fixed by bayonet couplings.
Side direction indicator lamps:
To replace the 2.5W bulb slide off the bulb holder
from the rubber socket located as shown in FIG 11 :19.
The bulb is secured by a bayonet coupling.
Number plate lamp:
To replace the bayonet coupled 5W bulb remove the
lens and light cap mounting screws as shown in FIG
11:21.
Lamps give insufficient light:
Test the state of charge of the battery and recharge if it
is necessary from an independent supply. Check the
setting of the lamps. If the bulbs have darkened through
age fit new ones.
Lamps burn out frequently:
If this is accompanied by a need for frequent topping-
up of the battery and high hydrometer readings, check
the charging rate with an ammeter when the car is
running. This should be around 3 to 4 amps. A reading in
excess of this calls for adjustment of the regulator.

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

Inner panels:
Imitation leather-lined masonite trim panels are fitted
to all versions of the new 500' models. The panels are
secured in the housing below the door window by means
of four stiff clips located at the top and seven spring clips
located at the bottom equally spaced around the panel
border. The fasteners are located in holes in the door
framework inner flange. The door framework has a plate
which should be bent downwards onto the trim panel
once it has been installed. This will ensure correct seating
of the trim panel in the door housing.
When the door trim panel is being reassembled ensure
that the tarred felt pad is cemented correctly on the door
inner flange so that any water that may seep in through to
the door interior from the window rubber weather strips
may be kept away from the trim panel which would
otherwise cause distortion and rapid deterioration.
12:4 Door handles and locks
The doors are provided with locks which are operated
by handles either from inside or outside the vehicle.
Removal of the lock is a straightforward operation but
upon reassembly the following procedure should be
followed:
1 Mount the handle assembly from the outside and
insert the washer onto the stud. Screw in the nut several
turns to allow correct handle-to-lock mating on final
fitting.
2 Arrange the locking handle dog so that it is horizontally
positioned and tighten the mounting nut.
3 Mount the lock to the door panel and secure w i t h three
screws and washers.
4 Fit the plate w i t h the t w o rubber guide blocks fastening
by the t w o screws.
Striker plates are fitted with shim adjustment to the
door pillars and are secured by three screws.
12:5 Removing window regulator and door glass
Window regulator:
Description:
The window regulator unit is of the lever and gear
control type which transmits crank movement to the
lifting lever using high ratio gears. When the operating
handle is rotated it rotates a pinion mounted on its shaft
which is in mesh w i t h a gear on the hub of which is
mounted a second pinion that meshes with the lever
toothed sector (refer to FIG 1 2 : 3) . At the end of the lever
a pin fitting locates in a guide rail mounted on the
bottom of the glass. When the crank is rotated in one or
other direction the glass is either lifted or lowered.
Regulator removal:
1 Depress the door lining panel so that the crank key may
be located. Remove the key and the crank handle.
2 Using a wide blade screwdriver prise off the trim panel
by inserting the blade between the panel and the door
frame taking care not to scratch the door paint.
3 Remove the intermediate protection lining.
F500129
FIG 12:3 Lefthand side door window regulator, viewed
from car interior
FIG 12:4 Location of window regulator in lefthand side
door panel housing
4 Release the screws securing the window regulator
to the door. Carefully tilt the regulator so as to dis-
engage the lever pin from the guide on the bottom of
the glass and lift away the regulator assembly.
Regulator reassembly:
To ensure satisfactory regulator operation carefully
lubricate the gears and the lever pin guide and also
ensure that the glass slides freely in its channels. To

NUT AND JAM NUT FOR
ADJUSTING PIN FRICTION
FIG 12:5 Ventilation panel lower pivot
FIG 12:6 Removal of windshield glass. Simply press
out as shown
reassemble the regulator to the door is the reverse
procedure to dismantling. The following points should
however, be noted:
1 Before the lining is refitted to the door panel ensure
that the regulator operates correctly. Ensure t h a t the
glass moves up and down in its channels without
excessive efforts required on the crank handle.
2 Once the lining is glued into place ensure that it
adheres evenly on the door so that the window
regulator operation is not interfered with at a later date
due to the lining becoming detached.
130
FIG 12:7 Positioning the windshield after tilting wiperblades
Door window drop glass and weather strip :
Description:
The door windows are fitted with swivelling front glass
ventilators and a drop rear glass pane. The 'new 500'
convertible is equipped with stationary type window rear
glass which is secured to the door panel by means of t w o
brackets and screws together with spring washers and
nuts.
Removal of door glass:
To remove the door window drop glass proceed as
previously described for removing the regulator assembly,
and t h e n ease forward the front glass guide and then
carefully lift away the glass.
Reassembly:
1 Fit Fiat No. 16 clips equally spaced all along the door
window flange.
2 Install the glass runway by inserting it in the rear and
upper side of the window groove. The runway is
fastened in place by the spring clips.
3 Install the glass runway, complete with the fabric lining
and secure it to the regulator frame on the top side
using self-tapping screws and on the bottom side w i t h
the bracket, screw, plain washer and spring washer.
4 Secure the gear type window regulator to the door
panel using the three screws, three plain washers and
three toothed washers.
5 Refit the window rubber weather strips which are lined
with fabric on both inner faces that touch the glass
pane. Lock the weather strips in place w i t h the Fiat
clips.
6 Replace the metal joint cap.
7 Fit and correctly locate the drop glass complete with
lower rubber weather strip, metal channel and run
plate for sliding travel of window regulator arm.

8 Refit the intermediate protection lining ensuring that
it is properly located and well glued. Refit the door
lining panel, key and crank handle.
Door ventilator:
The door ventilator comprises the glass, weather strip
placed between the glass and chromium plated frame,
the chromium plated frame together with pin and bracket
for upper and lower hinging, frame control handle and
lining.
To remove the ventilator glass first drill the upper pivot
pin using a portable electric drill and release the nut and
locknut from the lower pivot bracket. Carefully lift away
the glass.
Reassembly:
To reassemble the ventilator glass proceed as follows:
1 Coat the outer edge of the glass on which the chrome
plated frame must be installed with a 50% solution of
petrol and oil to ensure that the glass can be easily
inserted into the frame.
2 Install the lock handle which is secured to the frame
by means of a screw sunk into the handle body and
t w o corrugated spring washers placed between the
frame and the handle.
3 Before installing the ventilator pane on the door panel
ensure that the metal channels in the front post flanges
at the pane base are firmly located in place and f i t the
rubber weather strip arranging it carefully in its
seating. The weather strip is secured by clips located
on the metal channels.
4 Refit the handle striker plate and secure it to the door
channel by means of t w o self-tapping screws.
5 Insert the lower ventilator swivel on the door panel to
welded bracket. Fit the spring and secure ventilator
assembly through the nut, locknut and plain washer so
that it can, be freely adjusted to any position without
undue effort (see FIG 12:5).
6 Fit the chrome cover on the lower ventilator swivel.
Refit the upper ventilator swivel in the door panel
brackets and clench it using a hammer and a suitably
sized drift against a firm metal block. This will ensure
correct ventilator movement.
FIG 12:8 Adapting windshield weatherstrip. Simply
pull the draw-cord
F500
131 RUBBER BUFFER-HOOD LID LINING
BUMPER
FIG 12:9 Front compartment lid lining and rubber
buffers
HOOD STAY SPRING HOOD STAY HOOD HINGE LOCKING NUTS-
FIG 12:10 Close-up view of hood lid hinge and stay
1 2 : 6 Removing windshield glass
Removal:
To remove the windshield glass carefully push from the
interior of the car against the glass and with the assistance
of a second operator carefully ease the glass away f r o m
the glass aperture as shown in FIG 12:6.
Refitting :
1 Fit the weather strip onto the glass.
2 Insert a draw cord completely around the weather strip
outer lip. Ensure t h a t the cord ends come to the centre
of the lower edge of the glass.
3 Press t h e windshield assembly against the body
opening from the outside as shown in FIG 1 2 : 7 and
then carefully pull the cord ends from the inside so the
overlap of the weatherstrip will locate over the body
opening lip (see FIG 12 : 8).
4 Carefully replace the rear view mirror bulb cable
between the weather strip lip and the body panel from

SEAT RUBBER PAD
SEAT ARTICULATION SUPPORT
SEAT MECHANISM
CONTROL LEVER
SEAT SLIDING GUIDE
SEAT FIXED GUIDE
FIG 12:11 Sedan front seat
42
3
1
FIG 12:12 Sedan rear seat w i t h removable cushion
Key to Fig 12:12 1 Striker plate for triple acting door latch
2 Seat cushion 3 Dowels (two) for seat cushion location
4 Seat back
t h e rear v i e w mirror to the side of the dashboard.
5 Using a special compound sealing gun inject sealer
between weather strip outer lip and body.
12:7 Removing rear side windows
The rear quarter glass panes are located to the body
using the weather strips. To remove the glass simply push
outwards ensuring that a second operator is ready to
catch the glass as the weather strip becomes detached
from the body.
To reassemble the glass pane proceed as directed for
refitting the front windshield. Finally seal as previously
described using sealing compound.
12:8 Removing rear window glass
The rear window glass is removed and replaced in the
same manner as described in Section 12:6 for the
132
FIG 12:13 Centre catch of Sedan and Station Wagon
folding top. Dotted lines show the folding top control
handle in open position removal and replacement of the windshield glass.
Ensure t h a t the weather strip inner groove is thoroughly
filled using correct sealing compound.
1 2 : 9 Front compartment lid
The front compartment lid is hinged at the centre w i t h
the lower half of the hinge welded to the body upper
crossmember. The hinge upper half is secured to the
lower half by nuts and washers which are screwed onto
the lid studs. The compartment lid is kept closed by a
catch as shown in FIG 1 2 : 9 with an additional safety
hook to avoid accidental opening.
The catch release mechanism is controlled by a handle
which is located under the lefthand side of the instrument
panel and connected to the lock by means of a bowden
cable. The cable is arranged inside the front compartment
and the inner wire passes through a bracket and secured
to the catch. A return spring is fitted onto the catch, the
latter pivoting on a locked pin.
A specially shaped weather strip is arranged on the
front and side flange of the front compartment opening.
To refit and renew the weather strip ensure that all the old
bonding compound is removed using a stiff brush.
Spread fresh adhesive to the body shell and carefully
locate and press home the weather strip.
Six rubber bumpers are press fitted into the body shell
and at both ends of the front compartment lid to ensure
correct location and freedom of rattles.
12:10 Engine compartment lid
The opening and closing movement of the lid is con-
trolled by a locking handle. The lid opens downwards and
pivots on two lower hinges. The hinge pin is welded onto
the lid and its socket is welded to the body rear lower
crossmember. To remove the engine compartment lid
proceed as follows:
1 Remove the number plate lamp cable terminal.
2 Unhook the check strap by manipulating the retaining
cross piece.
3 Release the righthand pin self-locking nut and exert
a slight pressure on the righthand side of the lid so
pushing it towards the left.
Reassembly is the reverse procedure to dismantling.