Motor vehicle operational parameter display - has warning and display panels illuminated by single light source with adjustable brightness

The display has warning fields indicating the parameters for maintaining proper run of the engine, such as oil pressure, battery condition, fuel level etc. The optical state of the display fields is controllable by photosensitive elements, while a light source is provided for the display fields illumination. The warning (17,18) and the display field (19) are illuminated by a single light source (20). The light source is controllable manually and/or in response to other magnitudes, such as ambient light in order to provide an adjustable and controllable brightness. On activation of the warning field, the light source brightness is automatically increased. This may be achieved by a change in excitation of the photosensitive elements.