I don't have a potential solution, just some comparable issues.
I am on my second retro bird. The first was an 05 anniversary edition. This current one is a 'Galpinized' pink 02.
I have seen odd electrical issues with the
radio in both of them. The 05 had a volume knob with a mind of its own, sometimes worked, sometimes didn't. Other times I would start the car and the display on the
radio and heating/air would not come on. Then after driving for five minutes, it would light up and work just fine.
I have had an identical problem with the pink 02, and she has way fewer miles than the 05 had.
When I bought the 02, the guy at the classic car dealership said he has a Mustang of the same year and has already had to replace the
radio once. He said he had read that many Ford products had issues with radios in that 2000-2005 era.
These things are high maintenance at times, but worth the struggle, in my opinion. I figure that the
radio will just stop working one day and not come back on, and then I will have to let somebody dig into the dash and replace the thing, like that guy did with his Mustang.