just recently we have changed our stereo from the fiat stereo to a panasonic which was changed by my brother in law and since the new stereo has been put in the central locking does not work, surely fiat didnt put central locking wires through the stereo column, or did they, the fuses have been checked and replaced, we are fresh out of ideas, any suggestions.

Check the fuses etc, there's a relay you can check as well but i cant rem where it is.

On mine theres a yellow relay box behind the glove box. Maybe you knocked it or somthing and its not in properly?