Dash display goes dim then bright?

[portzy]

Hello, I have a peculiar problem with my SLK R171, driving with the roof up the LCD display constantly changes from dim to bright, (depending on the intensity of the outside light conditions - sunny/bright to overcast/dim etc), but the LCD never actually fails so I am guessing that there is an ambient light sensor located somewhere? which is playing up.

The confusion starts when I have the roof down, stowed that is, because the LCD display becomes bright and stays bright irrespective of the ambient light conditions. So, is there a sensor? and is it inside somewhere?

Thanks.

 

[whitenemesis]

There is a separate sensor for interior ambient light levels. IIRC it's part of the COMAND or audio head unit. Does the heating LCD also change?

I imagine when the roof is down the car disregards this sensor and sets all to bright to compensate for the much higher light levels

Not sure if STAR would pull up any error codes?

 

[portzy]

Does the heating LCD also change?

I'm not entirely sure. I'm only saying that because I got the upgrade a/c when new and to be honest the dual temperature LCD display has always been on the dim side, that is unless the interior is in say night time darkness then it seems to be okay from a visually "bright" perspective, but I'm guessing that in night time darkness it would "appear" to be bright any way.

The comand screen has three options, day - night - auto, I have this on permanent "day" which I find to be best for me so again one of my assumptions is that this may overide any sensors because the brightness stays the same whether the roof is up or down.