2006 Passat----Radio appears to work---no sound output? I've pulled the radio and checked the wire loom from the radio to the amplifier---wires are intact---and I show 6.05 Volts DC at the amp (grey plug) connections. (Why not 12 volts?). I see also that there is a blank plug on the back of the radio which is not being used---but no wiring loom plug anywhere in sight---leading me to believe that was never needed for this system. I am at a loss to understand why I've lost all sound (unless the amplifier itself has gone bad? The 10 amp fuse at the back of the radio is OK and the radio will toggle through it's normal sequence showing the display normally---but there is not so much as a squeak coming from any of the speakers. Is there supposed to be 12 volts ---not 6.05---at the amp connections? Any advise will be appreciated---I can find nothing on the internet that helps----and there is no break in continuity in the wiring loom as some of those video's have suggested to be the problem?