Car is a 92 400E. Front passenger window does not move at all. I can hear a clicking noise at the window when operating the switch. There's no sign of any stress, like a jammed regulator or something - just a slight clicking noise - like the motor is trying to kick in but it can't quite pull it off. It seems to me the console switch must be fine, or it wouldn't be able to generate a click at the window. And there's no sign that I can see that the regulator is not working.

So what my next step? - short of just buying a new motor and trying it out.