Hello; a while ago i installed an rns-e unit in a 2001 a6 with bose, cd changer, and xm radio. That car has now been replaced, and last night i installed the system in a newer a6, which had bose and the cd based nav system. Everything seems to work properly, except no sound comes out of the left channel (neither music nor the nav voice); and a slight hum can be heard from the left rear. All of the wires in the harness seem to be going where they should; i am wondering if this has anything to do with the fact that the car had a cd based nav system to begin with; if anyone has any insight into what might be causing this or how to remidy it, your input would be greatly appriciated. Thank you,
-John
-John