Alternator — General Information (VW Golf 1)

The generator is a device that produces electricity. It is located under the engine hood. All current consumers must be supplied with electricity. While the engine is not running, the battery supplies power to the consumers. As soon as the engine starts, the generator begins to work as a source of electric current.

The described Volkswagen models have an alternating current generator. It is driven by the engine via a V-belt. The generator produces alternating current. Since the battery is charged with direct current, semiconductor diodes perform the necessary rectification of alternating current. Diodes are sensitive to excessively high voltages.

Rules for handling the generator

When the engine is running, the cable between the battery and the generator must not be connected or disconnected, as this can cause the voltage to increase instantly (voltage peak), the diode will overheat and fail.

The generator cannot operate without a properly connected and functioning battery. The battery serves as a voltage limiter for the generator.

All connections in the generator-battery-ground complex without exception must be very securely fixed. Even one poor contact can cause voltage peaks.

Both wires should be removed from the battery when fast charging the battery or electric welding the body.

Generator power

In Volkswagen models, depending on the year of manufacture and special equipment, generators with a current of 45 to 65 A are installed. At a maximum voltage of 14 V, the power is from 630 to 910 W. Two-thirds of this power is already generated at 2000 generator revolutions. The generator rotates faster than the engine. With a gear ratio of 1:2, two-thirds of the power is developed at a slightly increased number of idle revolutions.

When you turn on consumers that need a lot of power, you notice this relatively high generator output. The idle speed drops because the generator is drawing more power.