Incorrect Radio Code: Some BMW models require a radio code to be entered after the battery is disconnected. If you did not enter the correct radio code, the radio will not turn on. You can find the radio code in your vehicle's owner's manual or by contacting your local BMW dealer.
Blown Fuse: A blown fuse can also prevent the radio from turning on. Check the fuses in the fuse box located in the trunk of your vehicle. If you find a blown fuse, replace it with a new fuse of the same amperage.
Loose Wiring: Loose wiring can also cause the radio to stop working. Check the wiring connections at the back of the radio and make sure they are secure.
Faulty Radio: If you have tried all of the above steps and the radio still does not work, the radio itself may be faulty and will need to be repaired or replaced.
