Citroen xm prestige

[Danmar]

Hi, i own a 92 (k) citroen xm prestige, i have a buzzing noise coming from near the sunroof switches which only goes when i press one of the buttons. Also i the a/c display is lit up with the temperature but as soon as i turn the lights on then it goes out and u cannot see the temperature, is this how is should be. Many thanks..