electrical on 1990 Cadillac DeVille

when i turn my car off and open my door sometimes my radio or my ac will turn on by them self sometimes draining battery

1 answer
The radio should turn off when you open the door. If it stays on there could be a faulty input to the Body Control Module, a sticking relay, or a faulty BCM. About the A/C, is the blower motor staying on? If so the cause is most likely the blower motor control module.