Would appear you amp isn't working correctly. Common problem on the X5, just got the problem myself. Sounds as if you need a new BM54, they often break because of solder damage and condensation.
Jake
August 2010
hi - did u get an answer to this - i have the same problem with a 525 - only the drivers door is working
phillip doran
May 2009
I can answer this question...
No sound from speakers on my BMW X5 factory fitted audio/cd player ?