Instrument Cluster Illumination, Location/Function

Illumination of instrument cluster
The illumination of the instrument cluster (A1) switches on automatically when it is activated. The details on the instrument cluster (e.g. displays, display instruments) are only clearly visible now due to the <>. It is activated by opening the driver's door for example or pressing the reset button.

The brightness of the illumination depends on:
- the brightness of the surroundings and
- the position of the instrument and search illumination rheostat (A1r1)

The figure outlines how the brightness of the illumination depends on the brightness of the surroundings and position of the instrument and search illumination rheostat (A1r1):
- In curve (a) the instrument and search illumination rheostat (A1r1) is on the right-hand stop (maximum value). As the brightness of the surroundings increases the illumination also becomes brighter. The possible range is from (min) up to the maximum value (max).
- In curve (b) the instrument and search illumination rheostat (A1r1) is on the left-hand stop (minimum value). As the brightness of the surroundings increases the illumination also becomes brighter. The possible range is from (bmin) up to the maximum value (max). However, the maximum value (max) is only reached here when the brightness of the surroundings is greater.

When the instrument cluster (A1) is activated the illumination always works/operates with at least the minimum value (bmin) and cannot fall below this.

As the figure shows, changing the instrument and search illumination rheostat (A1r1) causes a shift in the minimum value from (min) to (bmin) or vice versa.

Phototransistor
The instrument cluster (A1) has a phototransistor for automatically adjusting the illumination to the brightness of the surroundings. It is located under the fuel level gauge (A1p2).