Dashboard radio display and gear selector not lighting up

[gurrysir]

Hi guys
Need to bow to greater knowledge on here.
The display between the Rev o meter and speed o (above the dashlight display) doesn't light up when I turn on the ignition.

I have a s8 d2 2001. After around 20 minutes of driving the display slowly lights up to the full lumination. Also when I turn on the electrics at the ignition the sav navigation display breaks up before working fully..

Not sure if it's a fuse or something major. Any advice on what to try to fix it greatly appreciated.

I recently had a bluetooth media adapter to replace the cd changer? Not sure if this could be the culprit.

Thanks

Garry