General information about the charging and starting system (BMW 3 Series E46)

All vehicles covered in this guide have a 12-volt electrical system. The ground connection is via the negative terminal of the battery. The battery is located in the engine compartment or trunk, depending on the model.

A starter is used to start the engine. The starter switch is an integral part of the ignition switch and when turned on, it excites the traction relay installed on the starter.

The installed generator, depending on the engine, calculated the required maximum current (refer to Specifications), produced by Bosch or Motorola.

The generator is driven by the crankshaft via a ribbed V-belt. The regulator mounted on the rear cover of the generator serves to regulate the charging current.

The charging control lamp built into the instrument panel indicates that the electrical equipment is working properly as long as the battery charge is normal.