Volkswagen Golf/Jetta 2 manual

General information and precautions
Body electrical systems / General information and precautions

General information
The electrical system is of a 12-volt negative earth type and comprises a battery, an alternator with integral voltage regulator, a starter motor and related electrical accessories, components and wiring.

Further details of the various systems are given in the relevant Sections of this Chapter.

While some repair procedures are given, the usual course of action is to renew the component concerned. The owner whose interest extends beyond mere component renewal should obtain a copy of the Automobile Electrical & Electronic Systems Manual which is available from the publishers of this Manual.

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 Safety first! at the beginning of this Manual, observe the following when working on the system:
a) Always remove rings, watches, etc.

before working on the electrical system.

Even with the battery disconnected, capacitive discharge could occur if a components live terminal is earthed through a metal object. This could cause a shock or nasty burn.

b) Always disconnect the battery negative lead before working on the electrical system.

c) Before disconnecting any wiring or removing components, always ensure that the ignition is switched off.

d) Disconnect the battery leads before using a mains charger.

e) Do not reverse the battery connections.

Components such as the alternator or any other having semi-conductor circuitry could be irreparably damaged.

f) 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.

g) Never disconnect the battery terminals or alternator multi-plug connector when the engine is running.

h) Do not allow the engine to turn the alternator when the alternator is not connected.

I) Never test for alternator output by flashing the output lead to earth.

j) The battery leads and alternator multiplug must be disconnected before carrying out any electric welding on the vehicle.

k) Never use an ohmmeter of the type incorporating a hand cranked generator for circuit or continuity testing.

l) When carrying out welding operations on the vehicle using electric welding equipment, disconnect the battery and alternator.

m)When fitting electrical accessories it is important that they are connected correctly, otherwise serious damage may result to the components concerned.

Items such as radios, tape recorders, electronic ignition systems, electronic tachometers, automatic dipping etc, should all be checked for correct polarity.

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