How much power does a car radio consume? I have a bulky old radiogram thing that needs to go.. I have a spare car radio that I can wire up but what size ps will I need?

Just checked a radio that I have in the garage, (unused), it has a 1 amp in line fuse, so I would say a 5 amp power supply would be more than enough. May be wrong though, as definately NO auto electrician. Cheers Ray