1995 Lincoln Town Car radio issue

Noises problem
1995 Lincoln Town Car 4 cyl Automatic

hello, I know that my lincoln has some type of timer that will allow the radio to continue to play for up to ten minutes after the ignition has been turned off or until one of the doors are opened. Well it seems to have a mind of it's own because my radio will turn it self on well after the ten minutes has passed. Does it sound like I may have a short somewhere? I have to disconnect the battery cable when ever im not driving the car, that way I know the radio is not going to turn him self on and drain my battery. Can someone help with this issue PLEASE.