I believe this question might be able to be answered or guessed at by the pro's that have intimate knowledge of the 140. My local MB specialist just did the above R&R. The system now works fine with this exception.

The compressor and the center dash air cuts out at a certain accelerator pedal position. Other vents continue to blow air, so the blower is not cutting out. This is repeatable and always occurs at one position, which is slightly above light accerelation. Letting up on the pedal switches compressor and center vent air back on. This occurs at the same pedal position. It will occur regardless of indicated engine vacuum shown on the vacuum gauge in the dash. Seems to me that this could be a mechanical adjustment because it didn't do this before and I presume the electrical connections will only fit one way.

My shop is more than willing to try and figure this out, but I suspect they will be guessing. I'm trying to guide them to the answer.

Thanks in advance for any guidance as to what they may have mis-assembled.