I remember there being several doors up under the dashboard.
Look for the vaccum lines going to the actuators.
One of them is shown in this picture....just 1 orange colored vaccum line going to it.
This is on my 1996, so things might look a little different up under your dash.
This is behind the glove box, but there are several doors, so you will need to look around to find the one(s) not moving when you move the selector knob.
http://www.flickr.com/photos/4157486...57632198092975