Sound system is going in and out, speakers clipping on and off...

What is your question?

Anything that has to express any sound is effected and replaced by the speakers clipping and popping noises: CD, radio, phone, reverse gear alert bells, even navigation is clicking on and off?? I can't use the phone, listen to music, or use my navi in peace. It just started suddenly. Is it a fuse? If so, how do I know if a fuse is blown? Help!