Your car has many fuses that sends an electrical signal to your radio as well as lights in your car. When an electrical impulse is sent through the fuse that is to strong for your radio to handle, the fuse blows to protect the impulse from reaching your radio and damaging the electronics. Locate the fuse box in your car (owners manual) and remove the blown fuse. Take this into a auto parts store and ask for a new one. It has a VERY low replacement cost and is very, very easy to do yourself.
