Audio Systems: radio noise, radio harness, radio noise

Question
i was installing my radio in a 86 bmw, when i touched the yellow wire to the white on the old radio harness it made a pop sound and now the radio has a hi pitched buzzing sound. the radio still plays, but is this noise fixable? it turns out the white was a dashlight for the old radio.  

Answer
Todd,
You may have caused slight damage to the audio output IC, the cure to the problem is to replace the audio output IC. Any number of other defects could cause the buzzing sound, but a damaged output IC is the most likely.

TOM,
T&D ELECTRONICS