General information about the on-board electrical system (BMW 5 Series E28)

The electrical system of this vehicle is twelve-volt, with a negative ground wire. Power for the lighting and other electrical devices comes from a lead-acid battery, which is charged by the generator.

This Chapter describes the repair and maintenance procedures for various electrical components.

To prevent short circuits, fires and possible injury, always disconnect the negative battery cable before checking, repairing or replacing electrical components.

If your car radio is equipped with an anti-theft system, make sure you have entered the correct code before disconnecting the battery cable. Refer to Section Anti-theft audio system and instrument cluster language before disconnecting the wire.

If after connecting the wire, the inscriptions on your instrument panel appear in a language other than the one you need, refer to Section Anti-theft audio system and instrument cluster language, which describes the procedure for installing the required language.