1997 BMW M3

I have an issue with my lock,where I assume the fuse had blown but i have replace many of the fuse but my lock still hasn't work currently I have to lock all my doors manually i ask around and they say it the car locking relay but they don't seem to where its located and I obviously don't either So I wondering what seems to be the problem and my trunk is always unlock and my key don't seem to work with the car either I'm just confuse