The radio is missing its permanent feed, use a cheapo voltmeter and check that the Red wire is a permanent 12v and the Yellow is the 12v when the ignition is on. ( or vice-versa ). It is likely that the Red wire is 0v and hence a fuse...probably in-line has blown somewhere. If not then the cd/radio is not receiving the permanent feed correctly, don't suppose you have the model number handy. ( or a wiring diagram for it ).