I have a strange problem with my stereo where only the tweeters are plying i 3 of my doors (mid range seem to work in drivers door). I have the same problem with the old Stream MP3 head unit and my new Columbus unit. Checked the settings, faders etc on both players. Is it faulty wiring? Sometimes while driving some of the speakers come back to life for a brief moment.

Sounds like a dodgy wiring issue. But to remove the speakers you need to drill out the rivets