Espritman

In a prior thread, a number of listers helped me narrow down my problem of very slow then no shifting from hot to cold to hot air to the BEHR control unit located just above my right knee (on page 87-43 of Volume IV of the workshop manual). While still installed, I turned on the ignition and moved the hot to cold control lever on the dash while watching the arm on the control unit - no movement. I then started the car and tried the same procedure - no movement. Now that I have it removed, can it be tested any other way? If defective,can it be repaired. Any solutions other than new?
Thanks!
Bob
'88 S4 Auto Blk/Blk