I have an 04 1.4HDI 16V SX with auto air con. When set to LO the passenger side vents are very cold but drivers side are only cool. Outside air temp is about 19C or 20C. I have looked at the vent flap mechanism and it looks to be working correctly. I had assumed that they were from the same source, but I guess not. I'm refering to the dashboard level vents, not windscreen or footwell. I've got a Haynes manual but it's next to useless, no diagrams or photos. Any ideas ?