Electrical & electronics
Alternator
Generates electricity while a combustion engine runs.
Look for: The round aluminum housing and the belt pulley at the front.
Mounted on the engine’s accessory drive.
A rotating magnetic system produces electrical energy, rectified and regulated for the low-voltage circuit.
A belt-driven power station.
Charging warnings can come from the belt, wiring, battery, regulator or alternator.
Batteries and connections depend on age, charging and usage. Control units are diagnosed by faults, power and communications.
A fuse or connection differs from a coded controller. Identify the cause before replacing an expensive electronic module.
Battery-electric BMWs use a DC/DC converter instead of an engine-driven alternator.
BMW low-voltage systems across combustion, hybrid and electric models; equipment varies.
Same system