After sitting unused for a few weeks, on a very cold morning our car battery was completely dead. After recharging the battery, the radio was also dead. How do we get it to work again?!!
First, check the fuse, if blown, replace. If not and I doubt this will help, but you could try disconnecting the battery, with everything turned off, then reconnect. The cars’ ECM will have to ‘relearn’ it’s settings. Then if the radio works you will need to reset your stations. You may have to take it to a car stereo shop.
Wish I could offer more help, but todays systems are just too complex to diagnose without hands on testing.