1995 Lincoln Town Car dead battery

I have a 95 town car that the battery goes dead on if it has not been run everyday, I have found that the air compressor for the rear suspension will kick on even if the car is parked. At first I thought that this was the problem but have recently discovered that I can roll the windows down even with the key off. Also since the problem has started the radio will no longer shut off when the doors are opened (once ignition is shut off) and I have to cycle the ignition switch to get the radio to turn off. And about the same time the clock in the dash quite working. I know a lot of things wrong, but it seems to me that with all the problems happening at the same time that it may have a common problem.