stevdroid

Hi all. I have got a 2007 CL63 that came up with this mysterious issue. When the AC is off the seat functions works 100% of the times. When the AC is on, they will most likely stop working. No matter how I adjust the seat inflation thing it will just fall back to zero. The car is currently in a workshop, they have replaced the pump, checked AC and battery, tried swapping seat control modules, but nothing worked so far, and I was told the next step would be replacing the two seat control modules, which apparently doesn't guarantee to fix the problem. Has anyone here encountered this problem before? If there is any, how did you solve it?
Many thanks