Tonydell

The heat does not blow at any cycle on the drivers side. It blows Cold air - while the rest of the vents in the car get Warm air.
What is it?
Is there any kind of easy fix?

Chris411

Could it be one of the directional vanes is stuck where it diverts air. Possibly broken inside and locked to one side? Just guessing sorry

Proprof

Tony dell did you resolve this? I suddenly have the same problem

Leadfooter

It is a common problem that can come and go with the grinding of the actuator.

justnspace

iTrader: (1)

leadfoot is correct, the actuator/arm isnt working.

CSmoney28

Passenger side blend door must be stuck closed have it replaced by your dealer, make sure to negotiate for a better overall price.

russianDude

Do it yourself, I followed instructions and it took 30min, all you need is a screw driver. Part is like $40, dealer will be 250-300’min

CSmoney28

Is there a write up for it?

russianDude

I have SRM for RDX, I mostly used it, but I think someone did a write up with pictures, worth doing a search. It requires removing bottom of glove box and a pannel.

russianDude

Here is the part I used
79170-STK-A41

TheCanadian

My 2011 has begun to exhibit similar behavior. I've heard the mix door grind a few times - today i had no heat on the driver side until I cycled it back to a cold temp to "wake" the mix door.

CSmoney28

Thanks for the information, unfortunately I don’t have the service manual. The search feature also sucks on this site. I just ignore the noise until it stops working.

Tex Nomex

You'll usually hear moaning or clicking from the blend door in the weeks before the actuator locks up completely or breaks.
That's the time to fix the moaning with a couple of quick squirts of graphite garage door lube on the black slide surface behind the triangular blend actuator arm and into the slot of the actuator arm itself.

When you hear moaning:
Turn key to ON position. No need to start the car.
Set AC mode to Dual.
Crouch down outside the car so you can see the area beneath the dash above and to the right of the accelerator pedal.
Press the Temperature Down arrow and hold until the slotted white actuator arm bottoms out.
Spray dry graphite lube into the slot in the white actuator arm.
Press the Temperature Up arrow and hold until the white actuator arm moves all the way up.
Spray the black plastic housing in area that was covered by the slotted white actuator arm.

Using the AC arrows, alternate between moving the arm all the way up and all the way down to confirm the moaning is remedied.
You can also squirt a bit into the mouth of the actuator cable.
And if you look closely, you'll see a small white head on another plastic arm tucked away above this assembly. It's another plastic-on-plastic joint and you should lube this as well.
Takes less than 5 minutes.
No disassembly required.

If yours is clicking:
You've probably got broken teeth in your little plastic gearbox.
There are Youtube videos that detail how to open the gearbox and spin the gear around 180 degrees, moving the bad gear teeth out of service and allowing only good teeth to be used.

Good Luck.

CSmoney28

Thanks I need to do this

Bamahooty

Ok, I was reading this thread, but what about no heat on passenger side?? I have not heard any groaning or noise under the dash, but there is a big temperature difference between passenger and driver. I went ahead and ordered the part referenced above, but I wonder if I need something else.

Thanks and Roll Tide

Bamahooty

Hello everyone. I posted on this thread a few weeks ago about cold air on passenger side. I ordered the part 79170-STK-A41 that was listed by the Russian dude. The description lists it as passenger side blend door. When I got under the passenger dash, with the glovebox out, I saw a part with a different number on it than the one I bought. It had AW063700-8340 stamped on the part, while the new one (79170-STK-A41) had AW063700-8340 stamped on it. Either way, the passenger blend door was not as easy to get to as a YouTube video had made it seem, but I did see it work as I ran the temp dial up and down. So, now I am wondering if (1) this new part is indeed a newer version of the passenger blend door, (2) how would I even get to it if I did indeed need to replace it and (3) if the drivers side blend door is the one acting up (havent checked it yet). Either way, the heat is very sporadic and just within the last few weeks. In addition, we have a radiator failure last spring and I wondering if the heater core needs a good flush.

Any suggestions are much appreciated.

Thanks
Hooty form Alabama

CSmoney28

Maybe, this will help you!

Bamahooty

so, there are two blend doors; one on passenger side and one on drivers side?? Well, I still dont know if we have a blockage in heater core. The air is still cool, even when I was there behind the glovebox and felt the air coming thru the cabin filter direct from the heater core.

CSmoney28

There are four in the diagram I posted...

Bamahooty

sorry for the face palm, but two of them said "mix" so I wasn't sure if the other two, were something else. had no idea there are 4 blend doors/mechanisms in my 2008 RDX. Now, I have to find the other two.

CSmoney28

Bamahooty

Thanks for the enlarged picture. Looking at that diagram, I see a drain (and the drain is mentioned in another thread). I am assuming that can be accessed under the vehicle. I would like to flush the heater core, but the hoses going thru the firewall don’t seem easy to access (when I was younger, I wouldn’t have thot anything about tearing into it, but these days, I pay mechanics to do stuff I’m not comfortable with). Antifreeze level is good, so don’t think it’s that. Looks like all my blend doors are operating ok.

still puzzled. We don’t have cold winters here in north Alabama but my wife still likes her car to be warm inside..

thanks.

TheCanadian

If there is no heat at all and the blend doors are working, there is a cable from HVAC unit to the outside of the car to control a heater valve. That might've come undone.

Bamahooty

Mr. Canadian, thank you.

After further checking yesterday, we do indeed have heat through the dash vent (close to drivers window) on the drivers side. As you go to the left, the air cools quite a bit toward the passenger side. The air is NOT warm when only using the floor vent setting. I have verified that all blend doors are working when the dials/gages are adjusted EXCEPT, I can not see the operation of the blend door called passenger (#14 in pics shown above). It is underneath and behind structure, so maybe it is not working properly, but not sure how to get to it to even check it.