I've been faffing round with this for ages, I had a auto electrician come round and diagnose a blown speaker.......

So finally got round to fitting it tonight and the speaker sprung into life, but when I closed the door, the buzzing came back again

It has a Nokia CK-7W car kit fitted but i'm convinced its something to do with the wiring, so it wasn't a blown speak after all.

Anybody got an idea's what can be causing this ???