footwell strong air flow, windscreen vents/defrost hardly any

[Alexander]

I am trying to understand how the heating&Vent system works. Many things don't seem to work as expected.
The first problem I want to tackle is that if I put the mode switch in 'defrost', There is hardly any flow on the windscreen, while there is plenty in the footwell coming out of the back of the central console. I assume there should be plenty to the windscreen, and none at my feet...The choice between hot (bottom picture) and cold (top picture) does work. There is no vacuum leak hissing at all at the mode switch.
Suggestions where to start?

[Ron]

The Workshop Manual covers that fairly well. Download it from the Resources section HERE (https://www.dropbox.com/s/aud8p4bpj1ctjxd/DMC-WorkshopManual-Hybrid.pdf?dl=0). (It's large, so be patient.)
Section N:01:09 shows the position all the flaps should be in for defrost...

[Alexander]

The Workshop Manual covers that fairly well. Download it from the Resources section HERE (https://www.dropbox.com/s/aud8p4bpj1ctjxd/DMC-WorkshopManual-Hybrid.pdf?dl=0). (It's large, so be patient.)
Section N:01:09 shows the position all the flaps should be in for defrost...

I have the printed manual, and it is clear indeed. I assume it is the top left flap/actuator in the picture that is stuck. Is it possible to visually inspect if the actuator is moving? Can I get acces to it without taking out the whole unit?

[Alexander]

OK, I found the vacuum actuators in the drivers side of the central console. None seem to move whatever position I put the A/C heater settings. I wonder if I get vacuum supplied to the central knob. Continue searching, all help welcome

[MrChocky]

OK, I found the vacuum actuators in the drivers side of the central console. None seem to move whatever position I put the A/C heater settings. I wonder if I get vacuum supplied to the central knob. Continue searching, all help welcome

Pull out the vent hose under the glove box, and look in with a torch. Those metal doors can rust, unfortunately getting to them is a complete heater box rebuild, which is significant work to say the least.

Also have a look at the flag behind the glove far on the far passenger side - this can be removed and refurbished with only removing the glovebox.

[bueller]

You should probably check your mode switch first (the one you use to select defrost/vent/ac/etc.). It is common for these to wear out over time and can cause leaks in the vacuum line. If it's leaking there, you won't get any pressure to the different doors. If that is working properly, then it may be the vent door mechanics themselves that are rusted and this would be a more invasive repair.

[Ron]

...
I wonder if I get vacuum supplied to the central knob. Continue searching, all help welcomeIf you can get to the vacuum switch, check the hose with no tracer stripe for vacuum.