Whilst I'm waiting for my mig to return from having the rear wheel bearing done [1], I'm contemplating the final

repair to her.
The climate control *appears* to work OK - but no (or VERY little) air comes out of the vents.
The fan sounds to be blowing OK, and changes speed with the controls.
Using the "direction"(?) switch doesn't appear to make any difference - just a faint breeze (barely enough to disturb a candle flame) from all the vents.
I'm guessing that somewhere at the back of the dashboard are some sort of valves which control air flow to each outlet (feet, face or windscreen), and it has stopped working in some way.
I stripped down the passenger side glove box area to get to the fan motor, and I couldn't see anything which controlled the air flow, so where is it, and how do I get to it?
Also - are the flaps on the valves controlled by vacuum? because I still have a few issues with the vacuum hoses which control the multirams.
Could this problem be related?
[1](poor sod at the garage quoted me "two hours labour" - that was 10am, and he's *still* not finished taking the arm off at 16:45

)