1995, S-320 Climate Control, Mind of its own

[Marty-M]

After the car has been shut down overnight or 6 or 7 hours, when started the climate control system comes on like it normally would but after a few minutes it starts changing modes by itself. This will go on for several minutes then it appears to stick in a mode, could be any mode. Can not change modes manually once it reaches this point. After about ten to twenty minutes of driving I can shut the car down, make sure the displays clear, then restart and everything is find and operating as it should. The system will function normally in all modes until we stop the car and not start for 5 or 6 hours. Then everything repeats as I described. This started about 2 weeks ago. Several months ago I had an EGR problem that required cleaning the EGR pipe. Naturally I had to remove a number of vacuum lines. Could this climate control problem be related?

Any help would be greatly appreciated.