Mr Revhead wrote:
so sounds like its taking readings from thermistor sensor on dash, and thermistor sensor inside/under dash and trying to match the two by sending different temp air out the relative vents?
The one on the dash is a light sensor, not a temp sensor.
when it's up to temp it may put out warm air on your feet to keep the temp up,
and cool on your face to keep you awake.
What happens if you put it on full hot?