Flickering Lights?

[Melvyn]

Hi all,
I'm new to E30 Zone and also new to E30 ownership.
I have a 1990 320i Convertible, and also a 1993 320i Convertible.
I have a problem with my 1993 model insofar as when it is ticking over with sidelights on, the lights (including the instrument lights)
Flicker slightly. When the engine speed is increased, or when the headlights are switched on, the flickering reduces considerably, or even disappears.
Would be grateful for any advice,
Mel.

[Brianmoooore]

Usually down to a duff diode in the alternator. The output of the alternator consists of three equally spaced phases of an alternating current, which are then rectified by six diodes to produce a voltage which approximates DC. With a diode down, the DC component produced by one of the phases is missing from the output voltage, so there is a big dip in the output voltage once every turn of the alternator pulley, which is seen as a flicker on any lights that are on..