battery replacement FIAT 500 1971 1.G Workshop Manual

a n 0—20 v o ltmeter. If the circuit is in order the meter
should read approximately 12-volts.
3 Battery to fuse box terminal 30. Connect the volt-
meter between the terminal 30 and earth. No reading
indicates a faulty cable or loose connection.
4 Fuse box. Connect the voltmeter between the other
auxiliary terminal 30 and earth. No reading indicates a
broken or loose connection.
5 Fuse box auxiliary terminal 30 to terminal
number 30 on ignition switch. Connect the meter
between terminal number 30 on the ignition switch
and earth. No reading indicates a damaged cable or
loose connection.
6 Ignition switch. Connect the meter between termi-
nal 15/54 and earth. Switch onto the ignition position,
when no reading indicates a fault in the switch.
7 Ignition switch to low-tension cable connection
on the coil (blue cable). Connect the meter
between ignition coil terminal (blue cable) and earth.
No reading indicates a damaged cable or loose con-
nection.
8 Ignition coil. Disconnect the black low-tension cable
connecting the coil to the distributor side terminal at
the coil and connect the meter between this terminal
and earth. No reading indicates a fault in the primary
winding of the coil and a replacement coil must be
fitted. If the reading is correct remake the connections
to the coil.
9 Ignition coil to distributor. Disconnect the thin
black low-tension cable at the side of the distributor
and connect the meter between the end of this cable
and earth. No reading indicates a damaged cable or
loose connections.
10 Contact breaker and capacitor. Connect the
meter across the contact breaker points. No reading
indicates a faulty capacitor.
Capacitor:
The best method of testing a capacitor (condenser) is
by substitution. Disconnect the original capacitor and
connect a new one between the low-tension terminal on
the side of the distributor and earth.
If a new capacitor is needed, fit a new one complete
w i t h bracket, but if necessary unsolder the original bracket
and solder it onto the new capacitor using as little heat as
possible. Capacitor capacity is .15-.20 microfarads.
3 : 5 Removing and dismantling distributor (sedan
and sports)
To remove the distributor proceed as follows:
1 Rotate the engine slowly until the distributor rotor arm
is opposite the brass segment in the distributor cap
connected to No. 1 plug lead. This will provide a datum
for replacement.
2 Disconnect the cable from the low-tension terminal on
the side of the distributor body. Mark position of distri-
butor on support. Release the distributor retaining nut
and washer from the underside of the top flange of the
distributor support and carefully lift away the dis-
tributor.
3 Pull off the rotor arm. Remove the insulated terminal
assembly from the side of distributor body. Release the
contact breaker carrier plate retaining screws and con-
denser flange screw from the outside of the distributor
F50049 body. Carefully lift out the contact breaker plate
assembly.
4 Before further dismantling note the relative positions of
the driving dog and the rotor arm driving slot at the top
of the distributor cam spindle. The driving dog is offset
and can only engage its driving spindle in one position.
Then when the cam assembly is fitted to the centrifugal
weights during reassembly the timing is not 180 deg.
out.
5 Take out the cam lubrication felt pad recessed in the
rotor arm housing on the end of the cam spindle.
Remove the retaining screw, carefully disengage the
springs and lift out the cam spindle. It should be noted
that there is a small retaining ball and spring located in a
drilling nearly at the top of the drive shaft spindle.
Carefully lift away the weights.
6 Thoroughly clean all parts and inspect for excessive
wear. The distributor cap must not be cracked or show
signs of tracking. The cap terminals, rotor and contact
breaker points can be cleaned with a very fine file.
Emerypaper must not be used. If the clearance between
the rotor and distributor cap segments exceeds .0118
inch both the rotor and distributor cap must be replaced.
Inspect the contact breaker arm rubbing block for exces-
sive wear and also the points for wear so that if the gap
exceeds the last setting limit of .0209 inch and adjust-
ment through the stationary contact carrier screw is no
longer possible (see FIG 3 : 2) , the contact breaker set
must be renewed.
If the distributor drive shaft side or vertical movement is
excessive the distributor must be renewed.
Weak centri-
fugal weight springs or damaged weights must be
renewed using original Fiat spares otherwise the auto-
matic ignition advance characteristics could be altered.
FIG 3 : 3 Ignition distributor in place on engine SPARK PLUG CABLES
IGNITION COIL CABLE!
DISTRIBUTOR CAP
DISTRIBUTOR BODY
GROUND CABLE
CONDENSER
DISTRIBUTOR SHAFT
LUBRICATION FITTING
DISTRIBUTORSUPPORT-TO--CRANKCASE NUT
[MOUNTING SCREWDISTRIBUTOR
DISTRIBUTOR SUPPORT

TOOL A 62039
TOOLA. 62040 PIN WRENCH A. 52022
FIG 6:15 Adjusting ring gear-to-pinion backlash and
differential bearing play, using special wrench A.52022
reading on the dial gauge should be between .0031 to
.0047 inch. The actual clearance is adjusted by
screwing in one adjusting nut and screwing out the
other by the equivalent amount using Fiat spanner
A.52022 as shown in FIG 6:15.
4 Remove Fiat tool A.62041 and using Fiat support
A.62040 mount the special dynamometer A.95697 and
adaptor on the axle shaft. Rotate the axle shaft several
turns so seating the bearings and then check using
the dynamometer the rotation torque.
5 If necessary tighten or slacken the adjusters until the
specified torque of 1.01 ± .07 lb ft is obtained. This
operation must be very carefully carried out because if
one adjuster is set differently with respect to the other,
a variation in ring gear to pinion backlash may take
place, resulting in a variation of rotation torque. After
any adjustments always recheck on the ring gear to
pinion backlash and if necessary readjust and then
repeat the rotation torque check.
6 Finally check the tooth contact between the pinion
and ring gear as detailed in the following instructions:
Check and adjustment of tooth contact between
pinion and ring gear:
1 Carefully apply to the ring gear teeth a thin layer of
engineers' blue and gently rotate the differential whilst
holding the axle shaft firmly but allowing them to slip
slightly so as to have the unit working under load
conditions.
2 A contact impression will be left on the ring gear teeth
and the contact will be correct when the drive pinion
tooth contact pattern is evenly distributed on the ring
gear teeth as shown in FIG 6:16. Should the tooth
contact be incorrect the following observations should
be noted.
Excessive contact on tooth flank. Too deep
meshing — move pinion out from ring gear by reducing
thickness of shim.
Excessive contact on tooth heel. Too slight
meshing—move pinion in towards ring gear by
increasing thickness of shim.
74
6 : 8 Replacement of gearbox—differential unit
Installation is the reverse procedure to removal of the
unit from the vehicle as described in Section 6:2.
However, the following points should be noted:
1 Ensure that the clutch driven disc hub is correctly
aligned with the clutch shaft pilot bush.
2 The complete transmission unit should be carefully
pushed towards the engine and the clutch shaft
inserted into the driven disc hub splines and finally
home into the pilot bush. Extreme care must be taken
to ensure that no weight is placed on the clutch shaft
otherwise distortion may take place.
3 Carefully connect the gearbox rear housing to the
engine crankcase by using the studs, t w o of which
have special location dowels fitted. Screw home
finger tight the gearbox/differential to body to front
support mounting screws inserting the fibre washers.
Lower the hydraulic garage jack and pull it away from
underneath the vehicle. Screw in the four lower
mounting nuts and tighten to a torque wrench setting
of between 18.1 to 21.7 Ib f t.Finally tighten the front
support screws.
4 Reconnect the gear shift control rod and the speedo-
meter drive cable. Insert the springs between the axle
shafts and wheel drive shaft and tighten the
three
mounting screws of each splined sleeve on the
flexible joint to a torque wrench setting of 20.3 Ib ft.
5 Refit the flywheel housing cover. Replace the starter
motor together with its relevant cover and tighten the
two mounting nuts to a torque wrench setting of
18.1 to 21.7 Ib ft. Reconnect the starter control rod,
the t w o starter cables, the clutch control tie rod and
hook up the return spring and secure the clutch
control cable retainer bracket to the gearbox casings.
Reconnect the cable to the battery positive terminal
post
6 Lower the vehicle to the floor gently and then give a
thorough road testing.
6 :9 Swing axle shafts and slip joints
Description:
The t w o axle shafts are connected to the differential
unit through specially designed slip joints which allow
the shafts to swing and slide in the splined housing in
the differential side gear. At the other end, the axle shafts
are connected to the wheel drive shaft flexible joints
using a sliding sleeve. Excessive contact on tooth face. Too slight
meshing—move pinion in towards ring gear by in-
creasing thickness of shim.
Excessive contact of tooth toe. Too deep meshing
—move pinion out from ring gear by reducing thickness
of shim.
With all the above detailed cases, to adjust the pinion
by replacing the shim, the differential unit and drive
pinion shaft must be dismantled. This means that when
the unit is reassembled after the necessary adjustments
have been made, the backlash and bearing rotation
torque must be repeated.

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

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.