Chrysler Repair: CD changer: 300m, cable clamps, radio unit

Question
When I replace the battery in my 2001 300M, my 4 disk CD changer stopped working.  It will load and unload CDs, and all lights look OK, but it seems that the radio doesn't recognize that the CD changer exists.  I've checked the cables between the CD changer and the radio unit, but looks OK.  Is there some security code I have to reset somehow?  Thanks.

Answer
Hi Allen,
You are correct to check the cable connecting the radio and the CD player as that is the exclusive control pathway. There is a digital data control between the two on the violet/yellow wire between pin 3 of the CD and pin 4 of the radio plug. You might want to check the continuity of that wire. Another possibility is that the battery disconnect through it a loop. Try disconnecting the battery, and touch together the the two cable clamps for about a minute. Then reconnect and see if that might resolve that. The other wires that connect the two units might also be checked in the same manner. I don't see any reference to a code, but the owner's manual may have some info.
Roland