Radio and cd player light up but no sound after changing out the battery.

Sounds like you have a screwed up microprocessor. You could try to reset the unit by finding the main power and disconnecting it for 20 seconds. If you cannot find the power cable, you could try to disconnect the vehicle's battery for few minutes, then power up and see if that helps.

have u test the battery and the alternator?

have you had any speakers or bass boosters installed in your car that werent in the vehicle before you purchased. Watch for wiring issues or possibly even battery voltage issues.

Sounds very much like two possibles a short in the fuse box to the non working parts or your battery went dead and was recharged and you did not reset these items. As what U mention all sound like the equipment that needs to be reset when you change a battery or it goes dead.

dont replace this only needs reset look for reset button?

I HAD AN AN MVA IN 1/2009 (REAR ENDED ANOTHER VEHICLE) MY RADIO/CD PLAYER WORKED PRIOR/AND IMMEDIATELY AFTER ACCIDENT. THE NEXT DAY MY TRUCK WOULDN’T START, BATTERY WAS COMPLETELY DEAD. I RETRIEVED MY TRUCK 3/2009 ….. MY RADIO WILL PLAY, HOWEVER, I AM UNABLE TO CHANGE MODE FROM TUNER TO CD PLAYER, CD PLAYER JUST MAKES A NOISE AS IF ITS CHANGING DISK, THIS SOUND CAN BE HEARD WHEN I UNLOCK MY DOORS WITH OUT IGNITION ON; .....ANY SOLUTIONS OR ADVICES IS WELCOME

check the wirings of your speakers and then check the settings on your radio.

I’m happy to assist further over the phone at https://www.6ya.com/expert/ramy_d9e7ebea3891f482

kzingraff, I have a similar situation to Craig Waldie. I have a 2005 Durango and the CD player has not worked since I replaced the battery. Just like his 2004, the radio works perfectly, just not able to use the CD player. How can this issue be fixed?

Sounds like a wiring over load try rerouting the wires for cd player by running the hot wire to the battery and relocate the ground wire make sure the ire has enough amps and theres a inline fuse.