My car has 180,000 miles and was built for the USA. My AC was good last year and I just had it charged. It's nice and cold from all the driver side vents including defrost but it's quite warm on all the passenger side vents including defrost. I have the electronic climate control and no flashing lights on the dash. I suspect a temp sensor or a vent flap, any ideas on how to narrow it down? Thanks all Danny