Audio Systems: No volume in speakers, ford contour, amp power

Question
Tom,
I have a 1999 Ford Contour and the factory radio has quit working.  I decided to buy a panasonic model to replace it.  I bought a wiring kit and the power/ground, etc plugs lined up fine, but the speaker wire adapter did not match.  I cut the adapter off the car end of the wires and direct wired the speaker wires to the new radio.  The radio head works fine, plays CDs, tunes in stations, etc...The problem is there is no speaker noise what so ever.  I played with the volume, balance, fade, etc but nothing worked.  I am pretty sure the speaker wires are paired correctly.  I have installed about 25 radios over the years, and this is the first one I can not get to work.  When I cut the adapter of the factory wires, could I have displaced a ground for the speaker wires?  The speaker wires are all grouped together in a grey sheath, and there is a silver uncovered wire in the sheath.  I tried grounding this to the back of the radio but still nothing.  The volume worked fine on the old factory radio, it was the CD player that was busted.  
Thanks,
Josh

Answer
Josh,
The wire with the gray covering on it is the audio wire to the premium amp. The amp may be mounted in the trunk of the vehicle. The problem with the installation is that the new stereo will need an adapter to interface the head unit to the amp. The amp uses a remote turn on signal from the head unit to make the amp power up. You CAN NOT connect the speaker output wires from the new head unit directly to the factory amp by using the wires in the gray cable, doing so and then powering up the amp will cause to amp to burn up.

TOM,
T&D ELECTRONICS
tdeser@zoominternet.net