2004 a/c problem

automatic climate control. While driving either the driver or passenger side will go to full hot. It does not do it at the same time. One side will stay cold, and the back is always cold. If I shut the engine off and crank it back up both sides will blow cold again, and it usually does not happen for a couple of days after. really strange, and thanks for any ideas.

The auto dual zone system has to have the correct R-134a charge in it to work right.
Does you compressor kick on and off to much?
For more help.
Give us your low and high side pressure readings at idle and at 2K with compressor running.
Also vent tempt and outside air temp readings.
MT