With winter upon us, I noticed something odd about my 2010 IS350's HVAC system .....only half the car blows hot. My driver's side is fine, but the passenger blows cold even when I have the temp set at high. I found that the only way to remedy this is to turn the fan on full blast and then a "clunk" is made behind the center vents......boom, I've got heat on both sides regardless of how the fan is set.

Has anyone else experienced this?

 

Have you had the cabin filter changed recently, or did you recently buy the car? If you open the door to the cabin filter with the car not in recirculate mode it apparently damages the HVAC system. maybe this is related? Just a thought tho.

 

I bought the car from a guy who worked at a lexus dealership a few months ago. It is just about at 30k, so it's due for the cabin filter swap. I have the complete service history at 5k mile intervals and it doesn't say a cabin filter change has been done.

 

On second thought, the car had been serviced for the dash rattle issue and the dealership installed insulation. Maybe they damaged something when they had the center vents out.

 

Yeah i'd probably guess that's where the issue is from too. I was skeptical when they took apart my whole dash for that too! But luckily nothing was broken in my case.