bonnet FORD SIERRA 1983 1.G Engine Electrical Systems Workshop Manual

Never disconnect the battery terminals, or
alternator multi-plug connector, when the
engine is running.
The battery leads and alternator multi-plug
must be disconnected before carrying out any
electric welding on the car.
Never use an ohmmeter of the type
incorporating a hand cranked generator for
circuit or continuity testing.
Ignition and engine management
systems
Engine management modules are very
sensitive components, and certain
precautions must be taken to avoid damage
to the module when working on a vehicle
equipped with an engine management system
as follows.
When carrying out welding operations on
the vehicle using electric welding equipment,
the battery and alternator should be
disconnected.
Although underbonnet-mounted modules
(all except EEC IV) will tolerate normal
underbonnet conditions, they can be
adversely affected by excess heat or moisture.
If using welding equipment or pressure
washing equipment in the vicinity of the
module, take care not to direct heat, or jets of
water or steam at the module. If this cannot be
avoided, remove the module from the vehicle,
and protect its wiring plug with a plastic bag.
Before disconnecting any wiring, or
removing components, always ensure that the
ignition is switched off.
On models with underbonnet-mounted
modules, do not run the engine with the module
detached from the body panel, as the body acts
as an effective heat sink, and the module may
be damaged due to internal overheating.
Do not attempt to improvise fault diagnosis
procedures using a test lamp or multimeter,
as irreparable damage could be caused to the
module.
After working on ignition/engine
management system components, ensure
that all wiring is correctly reconnected before
reconnecting the battery or switching on the
ignition.
On some early Bosch distributors it is
possible that with the distributor cap removed,
if the engine is cranked, the cap securing clips
may fall inward and jam the trigger
wheel/vane, knocking it out of alignment. If this
happens, the distributor will have to be
renewed as the trigger wheel/vane cannot be
repositioned. Care should therefore be taken
not to crank the engine with the distributor cap
removed. Later distributors have redesigned
clips which eliminate the problem.
Removal
1The battery is located in the engine
compartment on the left-hand side of the
bulkhead.
2Disconnect the leads at the negative (earth)
terminal by unscrewing the retaining nut and
removing the bulb. Pull off the plastic cover,
and disconnect the positive terminal leads in
the same way.
3Unscrew the clamp bolt sufficiently to
enable the battery to be lifted from its location
(see illustration). Keep the battery in an
upright position to avoid spilling electrolyte on
the bodywork.
Refitting
4Refitting is a reversal of removal, but smear
petroleum jelly on the terminals when
reconnecting the leads, and always connect
the positive lead first and the negative lead last.
Testing
Standard and low maintenance battery
1If the vehicle covers a small annual mileage
it is worthwhile checking the specific gravity
of the electrolyte every three months to
determine the state of charge of the battery.
Use a hydrometer to make the check and
compare the results with the following table.
Ambient temperature:
above 25ºCbelow 25ºC
Fully charged1.21 to 1.231.27 to 1.29
70% charged1.17 to 1.191.23 to 1.25
Fully discharged1.05 to 1.071.11 to 1.13
Note that the specific gravity readings assume
an electrolyte temperature of 15ºC (60ºF); for
every 10ºC (50ºF) below 15ºC (60ºF) subtract
0.007. For every 10ºC(50ºF) above 15ºC(60ºF)
add 0.007.
2If the battery condition is suspect first
check the specific gravity of electrolyte in
each cell. A variation of 0.040 or more
between any cells indicates loss of electrolyte
or deterioration of the internal plates.
3If the specific gravity variation is 0.040 or
more, the battery should be renewed. If the
cell variation is satisfactory but the battery is
discharged, it should be charged as
described later in this Section.
Maintenance-free battery
4In cases where a “sealed-for-life”
maintenance-free battery is fitted, topping-up
and testing of the electrolyte in each cell is not
possible. The condition of the battery can
therefore only be tested using a battery
condition indicator or a voltmeter.
5If testing the battery using a voltmeter,
connect the voltmeter across the battery and
compare the result with those given in theSpecifications under “charge condition”. The
test is only accurate if the battery has not
been subject to any kind of charge for the
previous six hours. If this is not the case,
switch on the headlights for 30 seconds, then
wait four to five minutes before testing the
battery after switching off the headlights. All
other electrical components must be switched
off, so check that the doors and tailgate are
fully shut when making the test.
6If the voltage reading is less than 12.2 volts,
then the battery is discharged, whilst a
reading of 12.2 to 12.4 volts indicates a
partially discharged condition.
7If the battery is to be charged, first remove
it from the vehicle.
Charging
Standard and low maintenance battery
8Charge the battery at a rate of 3.5 to 4
amps and continue to charge the battery at
this rate until no further rise in specific gravity
is noted over a four hour period.
9Alternatively, a trickle charger charging at the
rate of 1.5 amps can be safely used overnight.
10Specially rapid “boost” charges which are
claimed to restore the power of the battery in
1 to 2 hours are not recommended as they
can cause serious damage to the battery
plates through overheating.
11While charging the battery, note that the
temperature of the electrolyte should never
exceed 37.8ºC (100ºF).
Maintenance-free battery
12This battery type takes considerably
longer to fully recharge than the standard
type, the time taken being dependent on the
extent of discharge, but it can take anything
up to three days.
13A constant voltage type charger is
required, to be set, when connected, to 13.9
to 14.9 volts with a charger current below 25
amps. Using this method the battery should
be useable within three hours, giving a voltage
reading of 12.5 volts, but this is for a partially
discharged battery and, as mentioned, full
charging can take considerably longer.
14If the battery is to be charged from a fully
discharged state (condition reading less than
12.2 volts) have it recharged by your Ford
dealer or local automotive electrician as the
charge rate is higher and constant supervision
during charging is necessary.
3Battery - testing and charging
2Battery - removal and refitting
Engine electrical systems 5•5
5
2.3 Battery securing clamp and bolt
Warning: The HT voltage
generated by an electronic
ignition system is extremely
high, and in certain
circumstances could prove fatal. Take care
to avoid receiving electric shocks from the
HT side of the ignition system. Do not
handle HT leads, or touch the distributor
or coil when the engine is running. If
tracing faults in the HT circuit, use well
insulated tools to manipulate live leads.