Rover 214 & 414 Service and Repair Manual - Rover club

5C•2 Starting and charging systems
1 General information and
precautions
General information
The electrical system is of the 12 volt
negative earth type and comprises a 12 volt
battery, alternator with integral voltage
regulator, starter motor and related electrical
accessories, components and wiring. The
battery is charged by an alternator which is
belt-driven.
The starter motor is of the pre-engaged
type incorporating an integral solenoid. On
starting, the solenoid moves the drive pinion
into engagement with the flywheel ring gear
before the starter motor is energised. Once
the engine has started, a one-way clutch
prevents the motor armature being driven
by the engine until the pinion disengages
from the flywheel.
Precautions
It is necessary to take extra care when
working on the electrical system to avoid
damage to semi-conductor devices (diodes
and transistors), and to avoid the risk of
personal injury. In addition to the precautions
given in the “Safety first!” Section at the
beginning of this manual, take note of the
following points when working on the system.
Always remove rings, watches, etc before
working on the electrical system. Even with
the battery disconnected, capacitive
discharge could occur if a component live
terminal is earthed through a metal object.
This could cause a shock or nasty burn.
Do not reverse the battery connections.
Components such as the alternator or any
other having semi-conductor circuitry could
be irreparably damaged.
If the engine is being started using jump
leads and a slave battery, connect the
batteries positive to positive and negative to
negative. This also applies when connecting a
battery charger.
Always ensure that the battery negative
lead is disconnected when working on the
electrical system.
Do not allow the engine to turn the
alternator when the alternator is not
connected.
Never test for alternator output by ‘flashing’
the output lead to earth.
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 vehicle.
Never use an ohmmeter of the type
incorporating a hand cranked generator for
circuit or continuity testing.
2 Battery - maintenance
Refer to Chapter 1 and “Weekly Checks”.
3 Battery -
testing and charging 2
Warning: Specially rapid ‘boost’
charges which are claimed to
restore the power of a battery in
1 to 2 hours are not recommended as they
can cause serious damage to the battery
plates through overheating.
Warning: During battery
electrolyte replenishment, never
add water to sulphuric acid
otherwise it will explode. Always pour the
acid slowly onto the water.
Warning: The battery will be
emitting significant quantities of
highly inflammable hydrogen
gas during charging and for approximately
15 minutes afterwards. Do not allow
sparks or naked flames near the battery or
it may explode.
Testing
1 In normal use, the battery should not
require charging from an external source
unless very heavy use is made of electrical
equipment over a series of journeys that are
too short to allow the charging system to keep
pace with demand. Otherwise, a need for
regular recharging points to a fault either in
the battery or in the charging system.
2 If the vehicle is laid up for long periods (in
excess of thirty days at a time) the battery will
lose approximately 1% of its charge per week.
This figure is for a disconnected battery. If the
battery is left connected, circuits such as the
clock (where fitted) will drain it at a faster rate.
To prevent this happening, always disconnect
the battery negative lead whenever the vehicle
is to be laid up for a long period. To keep the
battery fully charged, it should be given
regular ‘refresher’ charges every six weeks or
so. This is particularly important on
‘maintenance-free’ batteries, which will suffer
permanent reduction of charge capacity if
allowed to become fully discharged.
3 If a discharged battery is suspected, the
simplest test for most owners is as follows.
Leave the battery disconnected for at least two
hours, then measure the (open circuit, or no-load)
voltage using a sensitive voltmeter connected
across the battery terminals. Compare the
reading obtained with the following:
Voltmeter reading Charge condition
0.50 volts Fully discharged -
battery scrap
12.30 volts 50% charged
12.48 volts 75% charged
12.66 volts or more Fully charged
1689 Rover 214 & 414 Updated Version 09/97
4 If frequent topping-up is required and the
battery case is not fractured, then the battery
is being over-charged and the voltage
regulator will have to be checked.
5 If the vehicle covers a very 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:
Normal climates Tropics
Discharged 1.120 1.080
Half charged 1.200 1.160
Fully charged 1.280 1.230
6 If 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.
7 A further test can be made only by a battery
specialist using a battery heavy discharge
meter. Alternatively, connect a voltmeter
across the battery terminals and operate the
starter motor with the ignition coil HT lead
disconnected from the distributor and
earthed, and with the headlamps, heated rear
window and heater blower switched on. If the
voltmeter reading remains above
approximately 9.5 volts, the battery condition
is satisfactory. If the voltmeter reading drops
below 9.5 volts and the battery has already
been charged, it is proven faulty.
Charging
8 In winter when heavy demand is placed on
the battery (starting from cold and using more
electrical equipment), it is a good idea
occasionally to have the battery fully charged
from an external source. The battery’s bench
charge rate depends on its code (see a
Rover dealer or Lucas agent for details).
For most owners, the best method will be to
use a trickle-charger overnight, charging
at a rate of 1.5 amps. 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 and may cause a sealed battery
to explode.
9 Ideally, the battery should be removed from
the vehicle before charging and moved to a
well-ventilated area. As a minimum
precaution, both battery terminal leads must
be disconnected (negative lead first) before
connecting the charger leads.
10 Continue to charge the battery until all
cells are gassing vigorously and no further rise
in specific gravity or increase in no-load
voltage is noted over a four-hour period.
When charging is complete, turn the charger
off before disconnecting the leads from the
battery.