Audio Systems: New car stereo problem, 1998 chrysler concorde, chrysler concorde

Question
I just tried to install an Aiwa CD player in place of my original stereo in my 1998 Chrysler Concorde. I have done such an installation twice before on different cars, so I'm not a newby. I downloaded the wiring diagram with color codes from Chilton's online and everything seemed to be going smoothly. However, when I plugged in the new unit and turned it on, the display worked fine and showed that a signal was being received by the antenna, but THERE WAS NO SOUND! No sound came when I tried to play a CD either. My brother even took his Aiwa unit which had an identical plug and plugged it in...same problem...unit working, but no sound. We were both baffled.
I saw a similar problem on your website posed by a guy trying to install a Kenwood into his 1993 Concorde. Any answers? Thanks.

Answer
My suggestion would be to take a known good speaker with a pair of wires attached and connect it directly to one of the amp outputs at the back of the receiver.  That will verify the unit itself is working; then you must determine why the amplifier output is not reaching the speaker OR if the speaker(s) is bad.

You can check a speaker with a D battery or 9v battery directly across the voice coil and listen for a clicking sound.

Next, there may be an external amplifier in the car that must be bypassed. Some Concordes did; some didn't.

Let me know the outcome!

C