Hey All,

I tried to run my rear AC yesterday in my 03 R/T to find that only hot air was blowing out of the vents. The air is cold coming out of the vents in the front (all of the settings work), but the back vents feel as if the heater is blowing. It gets hotter the longer it runs. If I swith the control unit on the dash to be controlled by the rear controller, it makes no difference. This happend from using it one time to the next. It did not gradually become this way. Any ideas on what may be causing this? Any help would be appreciated. Thanks.

 

The rear evap maybe plugged, I don't thinkthe rear has an H-valve.

 

MP4ME:

There is a flapper door in the back similar to the front system that directs the air either through the AC or heater core depending on what is selected.
IIRC, the rear interior panel has to come out to access the unit, but once it is out the access is very good.

BTW, I have not done this myself thank goodness, but had read posts by others who have.

Don

 

Thanks for the info both of you. It does seem like the door being stuck in the wrong position scenario to me. At least I hope so. The evap would require pulling down the headliner right? Can you tell me the steps for removing that back panel? Does the third row seat have to come out to get it off of there? I have the side airbag option. If that makes any difference. Thanks again for the info.

 

Well whatever you do make sure to disconnect the battery and cycle the key a few times to drain any left over charge in the pcm so that the airbags don't go off on you.

 

MP4ME:

I do not have a factory service manual so I can't help you with the removal procedure. The manual most likely also has a diagnostic procedure you could try to help insure that is likely the problem.

Hopefully someone who has one can chime in here for you.

Don

 

I have discovered that I have a broken air blend door where the hot and cold passages are. I know this because I took the servo motor off and the shaft is spining freely 360 degrees. To verify this was the problem, I checked the floor/roof belnd door and it only traveled about 60-70 degrees and I could feel the door seat. So the other was broken by the torque of the servo over time. I am asuming it is all plastic in there. I also made sure my servo motor was still working, and it was. So in a way this is good news bad news. Good news in that the system itself is working, but bad news because I think I have to remove the whole airbox assembly to open the thing up to fix the door problem. I am assuming I have to evacuate the system to get the airbox out? Or is there a way to avoid that? Everything seems to be working fine except for that mechanical issue. I thought about just bypassing the rear heater core so the hot coolant would not even come into the box, but the broken door would still keep the cold air from coming through. Can anyone verify the AC line issue for me? As far as having to disconnect it to service the inside of the airbox? Otherwise, I think I have found my problem. Thanks.


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