I had a new alternator installed and now my car radio is locked and it's asking me to input a code. The service guy said this is because the battery had been disconnected and that the radio code ...

Then take it to a car stereo centre and pay them £30 to have it re-coded. You will probably need your V5 as proof that you own the car. The radio on my 2007 Ford Mondeo is stuck on 'one hour' mode, ...