Ok I have all the stuff I need to wire up the radio, but I need to know how to earth it. I have read some stuff about negative and positive earth but its a bit confusing. Where do you earth it too? The body or something else. I dont want to destroy it!
Rob...

fuse EVERYTHING, especially old stuff. You should be earthing to the body. Use a proper connector to do it. And make sure you add a new fuse regardless. Been learning that of late ... fuse EVERYTHING!.

Yeah thanks man I already have a new inline fuse holder for it so should be OK in that regard.
Its just the wiring set up Im a bit confused about!
Any more advice?
Rob....

red is power
black is earth
and usually green and grey are speakers .hope this helps

robo, does it say pos earth on the back? some you can change from neg to pos to neg ...whatever you like, I got 2 that you can change either way but some are set to pos and if you don't take it to a tech head and get it swapped over or you'll have to insulate it from the body which can be hard and unreliable.:duh

Rob

I think I have the wiring for an old Blaupunkt for my ghia, I'll dig it out and let you know. Red and black is normal, but they actually have a yellow wire from memory, but not sure if thats +ve or earth.

Angus