Hi!
We need your helpful advice and suggestions on ways to fix our 2004 Freestar.
Here's the problem:
When driving on the highway, at a constant speed, our freestar shutters a little bit only when the AC kicks on. When the AC compressor stops, the shutter goes away. In my opinion, its more than a shutter. The RPMs jump a little like they do when it downshifts.

This is what it seems like to me:
For some reason, the AC kicking on sends a signal to the transmission to downshift because of the increase load. The transmission attempts to downshift but another sensor does not allow the transmission to down shift. The shutter comes from the transmission getting mixed signals. Once the compressor shuts of, the signals are not mixed and the van runs like normal and goes back to overdrive.

It should be known that the vehicle, if it were running good, should NOT downshift in this situation.

Please give me any advice as to a possible fix for this problem. I have searched far and wide online and called the dealership. I have not had anyone with an experience like this.

Thanks