Hi everyone. As the title suggests the fan blower is malfunctioning in my S Max - currently the fan speed works, however it only blows out of the demister and only blows hot regardless of what setting it is on, and if the AC is turned on. 
It has the climate control and the buttons to select which mode, instead of the dial to select the mode if that makes a difference. My mechanic has said there aren't any fuses blown, but it sounds like the mode selector servo that has gone. 
Has anyone else had this problem, and if so what was the solution? Any help / ideas would be appreciated. Thanks!

As highly qualified as they are, you wouldn't visit your dentist to get a broken leg fixed !

It's unrealistic to expect a mechanic to diagnose and fix an electrical problem. It does sound as if the servo motor is not controlling the air direction, but it also seems that you are unable to adjust the temperature. The common denominator is the climate controller module.

You need to use FORScan to check for any DTC's or get an Auto Electrician to investigate the issue. 

Thanks for replying - turns out it was me being an idiot and not plugging the black and white cables back in properly when fitting an aftermarket stereo. 🤦🏼‍♂️