On-board electrical equipment — general information (Audi A4 B7)

The vehicles in question are equipped with a 12-volt electrical system with negative grounding. All lighting devices and electrical units are powered by a battery recharged by a generator.

This chapter describes the maintenance and repair procedures for certain components of the on-board electrical system, which in addition to the specific components discussed below, also includes all lighting fixtures and non-engine-related electrical accessories. In addition, diagnostic procedures for general electrical faults are discussed. Information on the battery, alternator, and starter motor is provided in Chapter 5.

Caution: When performing any repair or maintenance work on components of the electrical system, it is imperative to first disconnect the negative cable from the battery to avoid electrical injury and/or fire.