Power Window "Auto" feature

I have a 97 Venture and the drivers side window has the "auto" feature which is supposed to lower the window all the way without having to hold the button. I have followed the directions in the manual, but it doesn't seem to work. I just got this van, and I love it. This is the only thing that doesn't work (knock on wood!). Can anyone suggest what is wrong, and maybe suggest a fix? Could it be the switch itself?

Thanks for any help!