I have a friend at work and on his 2004 F150 his 6 Disc head unit would not take CDs so the local dealer replaced it under warrenty. Now his front speakers pop when he turns up the volume. He was told from the dealer the speakers were blown when he brought it in he disagreed but still bought new factory door speakers and it still does the same thing. Any ideas? I told him to take it back and have it fixed but he says he is to busy to take it back.

Scott