Help with '95 s320 a/c vents

[allegrobob]

I have a '95 s320 lwb with a vent control problem. When you turn on the a/c the top middle vents open and works fine, then after a couple minutes, they close and the air switches to the floor with no way to switch it back. The dealer says that there are problems with the servo controls and want's about $400 us to fix. Does anyone have any experience with this? How difficult a repair is it and can you point me to a URL with directions for dash removal. I've heard that you need special tools - is that true?

Thx

 

[television]

I will put some detail up later in the day.

Malcolm