I was wanting to know this a while ago too. I asked about the codes and ford here in shepp said none over 10 years old they have. They could send it off but that would cost about $70 i think! So i decided to hook up 12 volts to one of these radio's (the EA Ghia factory Radio), and in my spare time punched in 1111, 1112, 1113 etc. up to whatever number the code is. The radio turns on straight away when the right code is put in. To reset it after each time, disconect the 12V for a few seconds and turn on again. When there's no numbers, the radio is reset for another go! It is a VERY time consuming process, but it's cheap and it got the radio going! The most important step in this process is to write down the code once found, cause you dont wanna go through them all again to find it!
Hope that helps, if you can be bothered doing it!!!!
EA Fairmont Ghia : 3.9L MPFI, 2.5" cat back sports exhaust, K&N panel filter. Pioneer head unit, pioneer 4" three way fronts, Pioneer 6" 3 way rears, 2x 12" subs, blue interior light.
My main pride and joy : '76 XB Fairmont GS, 250CI, 140,000 Km and all stock.... for now! (Factory air-con on the way)