Hi I have an issue with the heater only blowing warm air on the driver side! I’ve been looking online and have come up with the heater blend flap actuator is possibly the fault. Does anyone know how hard it is to get to or even a how to replace the actuator on the s-max mk2 thanks. 

Unsure if the design has changed, this is latest I have (2006>)

It looks like a bit of a nightmare to get at?

In all of this, I can't see how the flow is split side to side which it must be?

Heat exchanger

The heat exchanger is accessible from the right-hand side of the climate control housing (LHD and RHD). It can be removed and installed with the climate control housing still installed in the vehicle. During removal, the coolant pipes of the production heater core must be sawn through. During servicing, a heater core with separate coolant pipes is installed.

Evaporator

The evaporator is located on the right-hand side of the climate control housing (LHD and RHD). It can be removed and installed with the climate control housing still installed in the vehicle, although the heat exchanger does need to be removed first. The refrigerant lines of the production evaporator must be sawn through during removal. An evaporator with separate refrigerant lines is installed in service.

Overview of the climate control housing

Item Part Number Description 
1 - Blower motor
 
2 - Pollen filter
 
3 - Evaporator
 
4 - Heat exchanger
 
5 - Electric booster heater (if equipped)
 
6 - Temperature control flap
 
7 - Air distribution flap, demister vents
 
8 - Air distribution flap, center vents / outlet vents on the B-pillars (if fitted)
 
9 - Air distribution flap - footwell
 
10 - Air inlet flap
 
11 - Air duct, demister vents
 

 
 

The actuators are mounted externally, cheap to buy used and easy to change.  The difficulty is working out which one is faulty.

Av6n-19e616-Aa Heater Box Motor Ford S-Max 2.0 D 103kw 6M 5P (2014 | eBay