You may have some loose or corroded connections
My wife went shopping today and when she came back she told me of an interesting situation with her 2000 Camaro. The electric windows do not operate until after about five minutes. Then they go up and down without a problem. I was also told that the radio will go off and then it comes back on and plays normally. (The radio is always left in the “on” position, whether or not the car is running.) She said the windows and radio have been acting like that for months. The car obviously has an electrical problem somewhere. Could the alternator be starting to go out?
The problem is most likely loose or corroded connections. I would start by checking behind the ignition switch. Make sure that the ACC terminal and wiring especially is clean and tightly connected. I would then check the power wire to the radio, and the wiring to the window regulators to make sure it is not frayed or shorting out against some metal part of the car. Finally, if the windows are operated by a relay or relays, I would test it to make sure it is working properly.
You may have to remove the door panels and clean and grease the window regulators and make sure that the windows are tracking properly too. If your alternator were failing you would most likely have bigger problems than the radio not coming on.