while driving, with the audio system off, suddenly I heard a loud explosion. next I heard what sounded like class breaking. I thought i was involved in an accident and slammed on my brakes. Realizing I was ok, the next thought that came to mind was that someone shot at me. The crackling sounds ( like glass breaking did not stop). i drive directly to a ford dealership. they heard and acknowledged the cracking sound. i turned off the truck and the sound CONTINUED.