Hello all and please be nice as this is my first post.
I own a 2006 Sonata, and have owned it since day 1. Currently at 250K miles with no major issues.
It is cold now and my daughter has noticed the passenger foot or face vents blow cold air. My side is hot and working as normal
The blend door actuator (Dorman 604-310) has been checked and is operable.
I have read that there are two Blend doors. I have not been able to find the location of the second blend door.
Is there another blend door that would control the flow of warm or cold air on the passenger side?
Please help my daughter our so she doesnt freeze with winter coming lol
Thank you

 

Update.
Second blend door on driver side has been located, and this blend door controls where the air is blown. (Defrost, feet, face etc)
I removed the hot/cold bend door actuator (passenger side) and moved the blend door by hand, and even with it fully shut, it is still not blowing warm air on the passenger side.
Is there a schematic or exploded view of the HVAC ducting anywhere?
I have a feeling maybe the door isnt fully closing, or if possible maybe there is a gasket in there that has deteriorated.
Any and all help is greatly appreciated.

Thank you

 

Sometimes there are no choices as to where to go next. It seems you are hot on the trail and need to get into that ductwork a little further. Careful checking and sometimes checking with a flashlight and mirror the problem can be determined without complete disassembly.

 

Update 2.
Merry Christmas. It is almost 70 F out today.
There is another Blend door (blue plug) above the first one I found (White plug), This one is located pretty much behind the passenger airbag.
How the heck does one replace this one? I removed the glove box, and the glove box surround. Still very difficult to reach.
I wish HMAService was still free.
Anyone have an idea how to replace this "upper" blend door actuator?

 

 

I haven;t replaced this one before, but from what I can see in the last photo,,,,,,with the blue plug and 3 wires, what if you removed the 2 screws that hold the electrical part in place, and then attempted to lift it off . I don't know how the arm is attached to the motor portion, but it appears the arm just indexes into a pivot point and you might be able to just lift it off.
Look at it this way,
If you can remove the motor part and shift the door to the max heat position you would at least have heat until you replaced the electrical part If that is what is broken.

Another thing you could consider is, Get a replacement activator and see where and how it is attached then you have some idea how far to go removing stuff.

I realize we don't know for sure if the problem is electrical or mechanical, but winter is on it's way and if we can't get it apart enough to know . At least if you see just how far you need to go and if you need the actuator , you have it and can finish the job.You could always continue removing pieces until you know for sure. If you choose that route you can use a test lite or voltmeter to confirm power is getting to the motor part. Then based on what you find there will determine if the motor is defective. What do you think ?

 

I have the same problem, do you solve this? Please tell me.

 

have the same issue? Has anyone come up with a fix for cold air on the passenger side?

 

the problem is a heat core.... i quess...

 

What about this?
I believe the heater core is common to both driver and passenger sides
If BOTH sides were cold the fast check would be to feel the heater hoses which at operating temp should be just about the same temp. If the core is restricted , one of the hoses would be quite a bit cooler than the inlet hose.What do you think?