I don't know if this will help anyone in here, but I have heard the CD players in the '93 Mustangs were notoriously defective. Mine would click non-stop like it was trying to eject a CD that was not in there....very annoying. It would not accept a CD player so I decided the CD portion was worthless....thus I decided to disect the radio in hopes of killing power the CD portion of the radio. Turns out it was VERY simple:
*Obtain a set of 1990's style Ford Radio Removal tools...these little "forks" if you will have two prongs, and fit in the two vertical oriented holes you see on each side of the radio.
*Insert the tools, pry outward toward the doors and the radio and storage bay will slide out. You have put the tranny 2, 4 or R (or move the shifter all the way down into gear for the AT's) and tilt the unit upward as it comes out.
*Disconnect the two harnesses and antenna wire and take the radio to your bench.
*Pry off the black plastic support guide (upward) on the back of the housing, and remove the two small torx screws on the back of the lid.
*Remove the lid and you will see the CD portion of the radio. On the left of the CD housing there is a slim, white harness connector. Use a small flat-blade and pry it off. Presto....you are done...CD player has been eliminated and the radio will still work.
*Reverse process, enjoy annoyance free radio....and crack open a beer!