Ok first off I have a 1985 Cadillac Seville with some electrical problems. If you are in the car with the doors shut listening to the radio and you open any of the doors the radio goes out and resets itself to 1:00 and 1400 AM. I've checked everything I can and found that the problem is coming from the door panel lights, whenever those lights come on the radio display power goes out. Also, the courtesy lights that are under the dash by your feet never go on when you open the doors like they are supposed to. But if you push in the main lighter in the middle of the dash, those courtesy lights come on. The lighter never gets hot it just acts as an on button for those lights. So here's how everything is related. If you are in the car with the doors shut with the radio on and you push in the lighter, the radio goes out. If you have the lighter pushed in so the courtesy lights are on and you open a door, the courtesy lights go out. Even if you turn the headlight switch to the left to turn on the interior lights the radio will go out. So some how those three things; the radio, the lighter, and the floor courtesy lights are related and do not work together. Can some one please help me? Thanks

I'm assuming it's the stock radio. Shot in the dark here...
It could be that somehow the dome/courtesy light circuit has been interrupted. At some point, the continuous memory for the radio has also been interrupted. Often it is on the lighter circuit. If you pull the LIGHTER fuse, what happens? If you pull the DOME/COURTESY LPS fuse, what happens? Those two results will point you in the right direction. I get the sense someone's been in there splicing wires, and might have switched the lighter circuit with the ashtray light circuit. It's worth noting also if the instrument cluster lights are affected in any way. You'll most likely need a wiring diagram. (Haynes/Chilton's is fine.) Once you've got it figured out, you should be able to simply tie the lighter in properly, as well as the courtesy lights. Good luck!

Did you find the yellow 20 amp body fuse blown? Did you find any tin foil or money in any lighter socket? a blown fuse would cause all of this weirdness.