Automotive electrical system

The alternator produces electrical current and charges the battery. If it fails, a red warning light with a battery symbol turns on on the dashboard. If the system is working properly, the light should go on immediately after turning on the ignition, and off after starting the engine. The most frequent causes of alternator failure include bearing seizure, diode bridge or voltage regulator malfunction or wear of its brushes. In each case, the alternator requires changing.