Body electrical system
General information and precautions
General information
The electrical system is of the 12 volt.
negative earth type. Electricity is generated by an alternator, belt-driven from the crankshaft pulley. A lead-acid storage battery provides a reserve of power for starting and when the demands of the system temporarily exceed the alternator output.
The battery negative terminal is connected to “earth” - vehicle metal - and most electrical system components are wired so that they only receive a positive feed, the current returning via vehicle metal. This means that the component mounting forms part of the circuit. Loose or corroded mountings can therefore cause apparent electrical faults.
Many semiconductor devices are used in the electrical system, both in the “black boxes” which control vehicle functions and in other components. Semiconductors are very sensitive to excessive (or wrong polarity) voltage, and to extremes of heat. Observe the appropriate precautions to avoid damage.
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.
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.
See also:
Master cylinder - removal, overhaul and refitting
Note: Before starting work, refer to the
warning at the beginning of Section 3
concerning the dangers of hydraulic fluid.
Removal
1 Disconnect the leads from the level warning
switch in the reser ...
Rear brake shoes - renewal
Warning: Brake shoes must be
renewed on both rear wheels at
the same time - never renew the
shoes on only one wheel, as
uneven braking may result. Also, the dust
created by wear of the shoes may ...
Speedometer cable - removal and refitting
Removal
1 Disconnect the battery and remove the
instrument panel as described in Section 9.
2 Disconnect the cable from the transmission
and release it from its clips and grommet.
3 Withdraw the ...
