Why would my 2001 Mercedes-Benz s430 blow warm air out of the left vents and cold air out the right air vents when the ac is on max cold on both right amd left sides?

The car has dual AC systems, you would have to check if the left side AC has a fuse burnt out or some sort.

Had the same problem and found to have a leak on passenger side of system. Shop charged $186.00 to recharge and replace valves and repair leak. blowing cold every since.