560SEL wierd electical problem

[Peter Kraft]

Hi folks, I have this '90 560SEL that has had this problem since I bought it a couple of years ago.

If I have the drivers door open and also my foot is on the brakes, then the buzzer will sound. If I close the door OR take my foot off the brake the buzzer stops. A few times the buzzer has started and stopped in a rythmic(sic) pattern and the engine will slowly die(removing my foot or closing the door will let the engine start right up with no ill effects).

I am afraid I'm going to break down one of these days because of this. What could this be? A bad ground?

Thanks for any comments any of you might have.