I have read everyone's posts regarding all of the CCU problems but none of them seem to match waht I have observed. Here is what I have found so far.

The control unit has no functionality whatsoever the buttons do not change moods, the temp wheel does not alter temperature and the fan controls do not change blower speeds.

As for the blower, no blower operation exists. I only have air coming from the defrost vents with no blower function. I have no A/C contol and the A/C unit does not even cycle on/off.

I have replaced the ignition switch feeling that it might have had something to do with it because the system worked fine when I got the car and then one day it just quit. I have replaced the voltage regulator and I have swapped out the CCU, all with no change.

At the fan plug up under the winsheild cover I have found the following:
Black wire to ground,, Red wire constant +12v
Yellow wire with fan on high +2.25v, on low +1.5 v and on AUTO +0.0v
Fuse #5 has +12v, Fuse #12 0.0v and Fuse D +12v
I also pulled the glove box and found good vacuum and have no other issues engine vacuum finne, door lock system fine etc..

DON"T KNOW WHERE TO LOOK NEXT
1988 260E if it matters