Quick lunchtime update:
- The flap is accessible on the Exige, just unbolt the fuseholder and take the two screws out of the rain gutter thing, it should then pull out - sort of like getting a square peg out of a round hole though.
- Once exposed, just pop off the ducting that carries airflow to the dash.
My flap seemed to be sat in the 'cold' position by default (car was switched off with it in the cold position, so makes sense):
I booted the car up and switched the dial to full hot, and sure enough the flap moved as expected.
Also did another test with the dial set half way and the flap moved to the half way position as expected.
So that's all a bit odd, no evidence of this being jammed at all and the control panel knob is clearly working. The only thing which was a little suspect was the wiring to the temperature probe (the probe sat in the AC evap radiator) was a little strained by a hard line which ran quite close to it - so I've gently bent that back into shape so the plug isn't being pushed on.
Maybe I'm just expecting too much from the AC system, everyone does say that it's crap after all and my attention towards it is probably heightened due to messing around with it so much over Winter.
I'll pay a bit closer attention to the rear of the car when my AC is next running, see if I can see any pattern in how the compressor is operating.