Help with Automatic door locking.

This is my first post here.

I have a 1995 Cadillac Sedan Deville and the problem is whenever i remove the key and lock the doors with the power locks, then close the door, in about a second, all the doors unlock themselves. Then I have to lock them again. If I don't lock them in the fist place, they still stay unlocked. I have read in the manual that the dealership can set it to lock or not whenever the key is removed and the door is closed. My question is, is there a way I can do that without taking it to the dealership?

It could be the the park position switch going bad. Do the doors unlock when you put it in park, and lock when it's in gear?

It does not lock when I put it in park, and also, I think that if it were the park position sensor, then it probably would not start in park. The doors even unlock when I start driving, instead of locking. It's as it's the reverse of what is supposed to happen.

I finally figured out what the problem is. The dumb power lock mechanism in the door is not locking the passenger doors all the way, even when I lock them with the clueless, I mean keyless entry thing. That would cause the dumb auto locking crap to unlock the doors. I suppose, I'll have to get new locking motors if I don't want to have to lock them manually all the time.