I have a 2010 rx350 2wd with 127000 miles. When put on heat the right passenger front dash blows cool air. What could be wrong? Thanks

 

Could be that what is sometimes called the dual climate control valve (DCCV) is stuck. Could also be that one or more of the servo motor blend doors is stuck.

 

Seems I have same model as @geoleo . However, mileage a little higher. When setting both driver and passenger to same temperature (or setting the driver side to the coldest temperature "Low"), specifically 68-71F. The passenger side is almost immediately blowing cold air. The driver's side is still cabin temperature, and after a while will start to get cooler. May take up to 30-45 minutes.

Please advise.

Thanks in advance.