# Sticky  FIX: Excessive Moisture/Condensation/Frost on Windows



## iKermit (Dec 13, 2010)

You are a genius and thank you for this amazing write up. Thank you Colt45 and Rob for making Lances brain turn!!


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## Jim Frye (Mar 16, 2011)

outfreakingstanding! Question: was your car always like this (assembly issue) or did it happen somewhere along the drive time (possible design issue)? I guess I'm asking if it happened once, can it happen again?


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## Blue Angel (Feb 18, 2011)

Jim Frye said:


> I guess I'm asking if it happened once, can it happen again?


My next trick will be to try and figure out how the flaps got out of sync with the HVAC controls in the first place.

My gut feeling is that it may have something to do with disconnecting the battery while the flaps are in the opposite position to where they're at during assembly? I have no idea, that's just a hunch and I'll have to experiment to see if that's the case.

It could be a defect in the HVAC module or a programming issue. I've heard several reports now where HVAC controls were replaced, modules were re-programmed, actuators and flaps were replaced... the fact that there appears to be no feedback from the actuator means that almost anything can be going on in there and neither the HVAC controls nor the driver are aware. My car displayed no signs of being "aware" of my tampering, even when moving the actuator by hand with the ignition on and the HVAC operational.

EDIT: To answer your question, I don't remember thinking one day, "Gee, there's lots of moisture in here." So I'm not sure if this was always like this or happened somewhere along the way?


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## spacedout (Dec 7, 2010)

Thank you for posting this, now you have me wondering so I can't wait to go take a look. My car has seemed to not get fresh air at times enough I added vent visors so I could equalize the inside/outside humidity without the heater or AC(no fogging or frosting).


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## au201 (May 18, 2013)

I went out and checked mine just now...mine are working correctly - June 2012 cruze. I have some fogging when it's cold and rainy, but I've always been able to take care of it in at least the front windows with fan speed 3 and fan speed 4 for a few minutes on only defrost would keep the back windows clear but I can't switch it off defrost or below 3 because it'll start to fog up again. I'm going to clean the inside of my windows and see if it helps. 


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## ChevyGuy (Dec 13, 2014)

au201 said:


> I have some fogging when it's cold and rainy, but I've always been able to take care of it in at least the front windows with fan speed 3 and fan speed 4 for a few minutes on only defrost would keep the back windows clear but I can't switch it off defrost or below 3 because it'll start to fog up again. I'm going to clean the inside of my windows and see if it helps.


Just to be clear, you have it set for fresh air? (Recirculate light is off) This fix just makes sure the car is doing what you tell it. You still have to run in fresh air mode to be moisture-free.


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## CruzeEcoBlueTopaz (Jan 5, 2012)

Just washed my car tonight in 30F weather and my windows all started to fog up. I crack the windows and they seem to clear up within a minute.

This time of year I regularly drive thru 0F to -15F cold weather for 45+ minutes at 55mph and my windows tend to stay clear. The exception is the driver side window begins to freeze up from the moisture I exhale. I crack a window or two and keep the heat close to max with the 3-4 fan setting and the windows stay clear.


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## spacedout (Dec 7, 2010)

Just verified mine has been working as it should. Still really glad to have checked, was already a dozen small leafs in the cabin filter I changed in October. Its also good to know if I ever have an excessive condensation issue, where to look for a possible cause. 

Thanks again for looking into this, I'm sure you will have helped many people with this.


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## jblackburn (Apr 14, 2012)

Just chiming in here - I never had a look myself, but the first couple months with my car the AC just sucked (was always in fresh air mode no matter what I pushed or did) and I could smell outside fumes constantly. 

Probably had something similar to what is going on in Blue Angels video, but my dealership determined that the HVAC head unit was "shorted" and replaced the head unit and the system has seemingly worked pretty well since.


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## ChevyGuy (Dec 13, 2014)

From reading the 2013 service manual:

The Air Recirculation Door Actuator (as well as the Air Temperature Door Actuator and the Mode Door Actuator) is a 4 phase stepper motor. I don't see any limit switch. However, from reading the text, it seems that the system does sense the range of motion end points - probably by monitoring the motor and detecting when it stalls. (There is a DTC code for stalled motor.)

While programming via a scan tool is preferred, it is possible to program it manually. This is the same for "manual" systems and "automatic" (climate control?) systems.



Clear all DTCs
Turn off car
Pull the HVAC control module fuse (F17 in the instrument panel)
Wait at least 10 seconds
Install fuse
Start car
Wait at least 40 seconds for self-calibration
If possible, check for any codes set by self-calibration failure


But we still have the question on how things get fowled up. I don't think pulling the battery would do it as it looks like it would just re-calibrate itself. Perhaps it's changing the HVAC controls before the calibration is complete. I also wonder about the possibility of leaf litter jamming the doors and giving a false range of motion. Or maybe the data gets corrupted somehow. I do find it odd that it opened the fresh air door when recirculate was commended. Unless it cycles when run past it's normal operating limits it would almost seem like the motor would have to run backwards.


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## 68554 (Oct 6, 2014)

Great post!! As I've only had my CTD back for a day now we will just have to wait to see what happens and how cold it gets here in Ottawa. My issue became very apparent with -30C temperatures. 

I concur please report this condition. In researching about condensation in these forums it appears many of you have had an issue with moisture and when I took my CTD back to the dealership they told me I was the first to mention this problem (and I have water coming out of the headline due to build up!!).


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## Robby (Mar 1, 2013)

Thinking about the 'Why did it happen' question.....I am tempted to speculate a relationship between the HVAC memory and that bloomin' negative cable or isolated body ground stud biz.

Manual said fuse out for ten seconds to force a re-learn.......I wonder if the momentary open ground circuit 'stuns' the HVAC module, causing it to lose orientation.....

Like I said.....just wondering if...,

Rob


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## Blue Angel (Feb 18, 2011)

ChevyGuy said:


> From reading the 2013 service manual:


Great info! I will be picking up my 2012 manuals soon for a cross reference, but I assume they will read the same.

Stepper motor makes sense; a given number of pulses would drive the motor a given distance. The question then becomes, how could the control teach itself to command the motor with the incorrect number of pulses?

It makes sense that the system can calibrate itself also. It seems to me that sometimes when starting the car the HVAC goes through a very long process of motors buzzing and flaps moving around. Maybe it's going through a calibration process? I'll have to observe the recirc flaps in action after pulling the fuse and see what takes place.


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## Robby (Mar 1, 2013)

I'm tickled my observations prove valuable from time to time.......Awsome post....great legwork BlueAngel.

I must apologize for failing to bring up one other tidbit that could be of value.

The discussion involved what is bringing the condensation into the car......we know that operating in recirculate, by intent or mechanical fo-pa, keeps and adds moisture.
This as well as damp floormats, winterwear etcetera, but I failed to mention one thing.

Be certain the spare tire well isn't carrying around a gallon of water from a seam or taillamp leak.
It happens often and is just as frequently overlooked.......I failed to mention it only because it was always the first place I looked when condensation was the concern.

Your heavily fogged window video started my memory juices flowing.

Rob


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## jblackburn (Apr 14, 2012)

> Be certain the spare tire well isn't carrying around a gallon of water from a seam or taillamp leak.
> It happens often and is just as frequently overlooked.......I failed to mention it only because it was always the first place I looked when condensation was the concern.


I had a leaky taillight too...GALLONS of water in there/the trunk carpet...


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## au201 (May 18, 2013)

ChevyGuy said:


> Just to be clear, you have it set for fresh air? (Recirculate light is off) This fix just makes sure the car is doing what you tell it. You still have to run in fresh air mode to be moisture-free.


Yes - always check to make sure im in fresh air mode when this happens. It's not too bad, but with two people in the car it requires fan speed 3 to keep it clear. 


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## ChevyGuy (Dec 13, 2014)

Blue Angel said:


> The question then becomes, how could the control teach itself to command the motor with the incorrect number of pulses?


A binding mechanism, possibly due to a small twig that came in with the leaf litter. Although Rob has a good point. Not to many years ago, you knew your battery was on the way out when the radio station memories got wiped after starting the car. (Battery voltage dropped too low.)





Blue Angel said:


> It seems to me that sometimes when starting the car the HVAC goes through a very long process of motors buzzing and flaps moving around. Maybe it's going through a calibration process?


Which begs the question - why?

Do you have the "climate control" or just regular HVAC? If climate control, then it may be sensing it needs to switch modes or something since the car is now at a different temperature than when you parked it.

Reading though the manual, the number of sensors surprises me. There's a sensor to shut off fresh air if you're behind a smelly truck.


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## au201 (May 18, 2013)

Blue Angel said:


> It makes sense that the system can calibrate itself also. It seems to me that sometimes when starting the car the HVAC goes through a very long process of motors buzzing and flaps moving around. Maybe it's going through a calibration process? I'll have to observe the recirc flaps in action after pulling the fuse and see what takes place.


Pretty sure this is just the HVAC controls going to what you have it set at because after 10 minutes of the car being turned off, the HVAC controls revert to a default set position every time, therefore they have to reset back to what they're set to when the car is started. I've sat in my car for 10 minutes after turning it off before and I noticed after 10 minutes I heard the noises of actuators and motors running behind the dash. Definitely the HVAC controls. 



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## ehousel (Nov 1, 2013)

Im going to speculate that the module got logic locked from turning the ignition off half way through the door moving or a loss of com with actuator, It probably wouldnt reset itself in these cases as it would still think its learn values were valid. Definately really weird though.


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## BowtieGuy (Jan 4, 2013)

Just checked mine, operating as designed. No moisture problems here either.


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## Blue Angel (Feb 18, 2011)

Haha... I forgot to mention a very basic but very important point in my thread:

You can't watch the recirculation flaps move if you're in defroster mode!

You have to have the vent selector set to anything but defroster mode to get the recirc flaps to move. The HVAC system will automatically go to the fresh air position and stay there if the defroster mode is selected, regardless of which recirc mode you've selected.

Will update original post.


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## Colt45 (Jan 4, 2014)

Thanks for the link to Transport Canada. Just logged my official complaint. Hope other owners do to. I also posted some new info in the "First World Problems" thread too.


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## Blue Angel (Feb 18, 2011)

Colt45 said:


> Thanks for the link to Transport Canada. Just logged my official complaint. Hope other owners do to. I also posted some new info in the "First World Problems" thread too.


Thanks, got it. Disregard my PM if that's the same document you were referring to.


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## Colt45 (Jan 4, 2014)

Same document....simply put, if it is not due to the bled door issue, you are screwed. If it is the blend door fix that you have come up with, then the owner is fine.

This also is affecting all the TRAX suv's but not the Buick Verano. Which means that since the Buick shares the same platform as the Cruze, it all leads back to the 1.4 Liter motor. The Buick uses a much larger displacement motor and it has no issues. In fact, it has great heat. My brother has one.


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## Blue Angel (Feb 18, 2011)

Colt45 said:


> This also is affecting all the TRAX suv's but not the Buick Verano. Which means that since the Buick shares the same platform as the Cruze, it all leads back to the 1.4 Liter motor. The Buick uses a much larger displacement motor and it has no issues. In fact, it has great heat. My brother has one.


I just rented a Verano for a week long training trip to Toronto. Yes, the car heats up very quick. It also burns more fuel.


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## Justinus (Aug 18, 2014)

I checked mine today. It was offset so on fresh air mode, the fresh air door was only open a few mm and the recirc door was closed. when changing modes, the fresh air door opened then closed to the same position while the recirculate door opened.

I tried the fuse reset and it was still wrong after the self-calibration so I turned the gear by hand to align the doors properly and it seems to work now, although I'll be re-checking it in a week or two to make sure it stays that way.

Seeing as how the fresh air door never opened more than a couple mm, a lot of things make a LOT of sense now. My car always smelled dusty in fresh air mode, and once the car was hot, I could never get cool air coming in from outside. I figured it was a really bad case of heatsoak, but now I see that I was never getting any notable amount of air from outside in the first place.

I went for a brief drive and everything smells so much better. Fresh air makes such a big difference.


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## ls3c6 (Oct 15, 2011)

Checked mine today, mine was just the opposite... going to recirc mode the gear doesn't move much and still stays partially open. I manually found a medium ground so both modes are acceptable but the motor doesn't seem to move the gear enough. Does pulling the fuse and making it relearn resolve this? I had the hvac unit updated last year for an unrelated problem of the sun load which there is a tsb for on bright days.


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## ChevyGuy (Dec 13, 2014)

ls3c6 said:


> Does pulling the fuse and making it relearn resolve this?


Should. But if there's a mechanical issue, it won't fix that.


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## KOBALT (Nov 19, 2013)

I'd also like to point out that wet floormats will have an effect. If you get in with a bunch of snow on your feet and it melts and saturates your mats, the moisture will rise and cloud up your windows and eventually freeze if it's cold enough outside. This is one reason why I don't use the rubber floormats(or weathertechs) in the winter. All that snow melts and just leaves puddles of water on your floor after you turn your car off.


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## ChevyGuy (Dec 13, 2014)

KOBALT said:


> I'd also like to point out that wet floormats will have an effect. If you get in with a bunch of snow on your feet and it melts and saturates your mats, the moisture will rise and cloud up your windows and eventually freeze if it's cold enough outside. This is one reason why I don't use the rubber floormats(or weathertechs) in the winter. All that snow melts and just leaves puddles of water on your floor after you turn your car off.


What's the alternative? If you track snow in, the same thing will happen regardless of what floor mats you have. The rubber mats just make it easier to dump the snow/water.


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## ls3c6 (Oct 15, 2011)

Removing fuse for relearn didn't do anything, it causes fresh air to be max fresh air and recirc to be still 15% open. Still had to adjust gear manually. There's no mechanical problem it just doesn't command the gear enough


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## Blue Angel (Feb 18, 2011)

ls3c6 said:


> ...the motor doesn't seem to move the gear enough. Does pulling the fuse and making it relearn resolve this?


I'm not sure. This is the condition the dealer can fix through "re-programming", whatever that involves. If pulling the fuse has the same affect as disconnecting the battery for extended periods, I can say with some confidence it won't help. I had my battery disconnected several times leading up to the discovery.


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## Blue Angel (Feb 18, 2011)

ChevyGuy said:


> Should. But if there's a mechanical issue, it won't fix that.


It would seem that re-programming the HVAC has cured this issue for several people in the past. I believe the HVAC controls are to blame when the actuator has insufficient travel.


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## Blue Angel (Feb 18, 2011)

ChevyGuy said:


> If you track snow in, the same thing will happen regardless of what floor mats you have. The rubber mats just make it easier to dump the snow/water.


I have to agree. In my opinion, keeping moisture out of the mats is easier when you can dump them out.

Though keeping sources of moisture out of the car will help, if the root cause is a lack of fresh air through inoperative recirc flaps, your car will freeze up no matter HOW dry your floor mats are.


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## D Cruzer (Feb 20, 2015)

Blue Angel said:


> For some time now there have been many Cruze owners posting about excess moisture inside their Cruze, leading to foggy or frosted up windows that compromise outward visibility. My car was no different and I assumed, as most did, that it was somehow related to the small engine not putting out a lot of heat.


Isn't there or shouldn't there be a TSB so that the dealer can correct this problem?

My late built Diesel has been doing this here in So Cal ever since I bought it and the dealer has no clue how to correct it!

Regards,

Derrel


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## LiveTrash (May 24, 2015)

I had this problem most of this past winter with my Cruze Diesel. It only appeared to happen half-way through the winter however. I'm hoping this is the issue. I'll be taking a look at it tomorrow and if the issue is present, I'll be taking it to me dealer for re-programming.

EDIT: Checked out the flaps today after work and they are moving fine. I guess it's something else...

Just to clear things up, circulating the air is what fogs up the windows, correct? Dragging the fresh air from outside (even if it's humid) will help remove the foggy windows?


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## ChevyGuy (Dec 13, 2014)

LiveTrash said:


> Just to clear things up, circulating the air is what fogs up the windows, correct? Dragging the fresh air from outside (even if it's humid) will help remove the foggy windows?


Assuming the outside air is cold, it's not going to have much moisture. And once it warms up in the car, it will be quite dry. 

But if you're talking about a day at 80F and 80% humidity, uh, no. The outside air will have a ton of moisture that will need to be wrung out of it.


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## Blue Angel (Feb 18, 2011)

LiveTrash said:


> Just to clear things up, circulating the air is what fogs up the windows, correct? Dragging the fresh air from outside (even if it's humid) will help remove the foggy windows?


Absolutely. As soon as I corrected the position of the flaps my car defrosted almost immediately.

However, like ChevyGuy says, if the outside air is already too moist and your windows are fogging up, the only way to correct that will be to run the AC to dry the air out. The Cruze automatically switches on the AC when the selector is moved to full windshield defrost for this very reason, as do most cars.


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## Blue Angel (Feb 18, 2011)

D Cruzer said:


> Isn't there or shouldn't there be a TSB so that the dealer can correct this problem?
> 
> My late built Diesel has been doing this here in So Cal ever since I bought it and the dealer has no clue how to correct it!
> 
> ...


Have you been able to verify the position of the flaps is correct? Check the videos I posted if you haven't already. With the cabin air filter removed the flaps are easy to see with a flashlight.

If it is extremely humid outside the only way to defrost will be to use the AC. If it's happening on days that are not really humid you likely have an issue.


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## OnTheCape (Sep 11, 2015)

I have a 2014 Chevy Cruze... just 6 months old. I am getting huge amounts of condensation on my outside windshield, just above the air vents. The opening in those dash vents blow air-conditioned cold air onto the windshield. The only way I can control it is to keep a folded up bath towel laying on top of the vents. Any other kind of towel isn't thick enough. I've been to my Chevy dealer. He said they ran some diagnostic tests that did not come up with any errors. The condensation is HUGE, and it's happening when it's humid. I've never had a car that does this. There doesn't seem to be any control whatsoever with those dash/windshield vents. No matter what direction I set the vents to (feet, upper combo of both), the same amount of air whooshes up through those vents. It's a nightmare... I already spoke to someone at Chevy Customer Care. They're the ones who set me up with today's appointment. Any suggestions?


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## jblackburn (Apr 14, 2012)

However they designed the HVAC diverter system, it leaks a little bit of air through that windshield vent. I think they all do that, and I don't know that there is a fix. Maybe it was intentionally designed that way to keep the windshield from fogging up on the inside. It is really annoying on humid evenings though.


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## OnTheCape (Sep 11, 2015)

Here's a picture. And thank you for your input.


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## jblackburn (Apr 14, 2012)

OnTheCape said:


> View attachment 163234
> 
> 
> Here's a picture. And thank you for your input.


I give the wipers a flick well before that happens!


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## mdubord1024 (Sep 3, 2014)

Mine does something similar. Even using the wipers only gets rid of it for a few seconds and it immediately returns. I have resorting to blasting the heat and rolling down the windows when it happens almost every morning on my commute. Also, don't know if you ever noticed but if you put it on defrost and turn the ac off, it still blast conditioned air, unless it's on a hot setting 


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## OnTheCape (Sep 11, 2015)

Same thing with me about the wipers. It gets rid of the condensation slightly, but comes right back. Using the windshield-wiper fluid helps a little. We shouldn't have to resort to putting a defrost or defog (which requires a warmer setting) when it's warm and humid outside. And yes, I also noticed that shutting off the AC & using defrost that there's still cold air unless the hot setting is on. When the AC is on, there shouldn't be so much air coming out of those vents near the windshield. Besides us, there's got to be other people going through this. Chevy should do a recall and have this fixed. It's not good when you can't see out of your windows on a humid day just because you're trying to get some comfort from your AC.


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## jblackburn (Apr 14, 2012)

> Also, don't know if you ever noticed but if you put it on defrost and turn the ac off, it still blast conditioned air, unless it's on a hot setting


Yeah, all modern cars run the AC compressor when defrost is selected and it's above 36-37F outside.


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## ChevyGuy (Dec 13, 2014)

You can try the HVAC Reset outlined in this post up thread. While that conversation was about the recirculating flappers, the process resets all flappers - including the ones that control the ducts. It's worth a shot.


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## BlueTopaz (Aug 25, 2012)

Found this thread. Good information for sure, thanks! Only thing is I checked my HVAC flaps and they work as advertised but this morning. It was 55 out, felt great going to the gym. All was well, drove the 25 miles to the gym with just fresh air on. Came out to the car an hour later after working out and the windshield and back window were fogged up. Took a good bit of driving with defrost on to clear. The back window I used the defogger and it cleared up. So it seems that my flaps are working like they are supposed to but there is still an issue. 

We have not had any rain for a few days, the inside of the car is dry and it is garaged over night. So now to troubleshoot why I get the condensation on the windshield like that.


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## ChevyGuy (Dec 13, 2014)

BlueTopaz said:


> We have not had any rain for a few days, the inside of the car is dry and it is garaged over night. So now to troubleshoot why I get the condensation on the windshield like that.


Check spare tire well for water.


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## OnTheCape (Sep 11, 2015)

ChevyGuy said:


> You can try the HVAC Reset outlined in this post up thread. While that conversation was about the recirculating flappers, the process resets all flappers - including the ones that control the ducts. It's worth a shot.


I just tried that today. Same amount of air is coming up through the windshield vents... even when I choose the pointing to the floor button. I was at my Chevy dealer last Friday and was told everything checks out fine. No error codes coming up. I am a woman in my 60's and I hope I'm not getting the runaround. Thanks for the suggestion though.


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## 87 (Nov 2, 2010)

Thanks for the great info and videos!

Decided to go check mine out since my 2011 1.4L has always seemed to have this problem. I just thought it was normal.

Low and behold regardless if in fresh-air or recirculation mode my recirculation flap is suck open, and my fresh-air flap is stuck closed. While in recirculation mode I manually turned the actuating gear downward all the way, but that didn't solve the problem 

I didn't read the note at the end of your post until now (about how when in defrost mode it will default to fresh-air mode) unfortunately, but regardless as I was testing this while defrost was on my fresh-air flap still wasn't opening.

Unfortunate thing is that this most definitely has been an issue since initially buying the car, but my warranty is now up.

EDIT - Oddly enough though I noticed (as I did about 25k ago while changing the cabin air filter) that there were some leaves and other outside elements in my cabin air filter. Wouldn't this be free of that stuff if the fresh-air flap was stuck closed?


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## thespr (Feb 21, 2016)

ChevyGuy said:


> From reading the 2013 service manual:
> 
> The Air Recirculation Door Actuator (as well as the Air Temperature Door Actuator and the Mode Door Actuator) is a 4 phase stepper motor. I don't see any limit switch. However, from reading the text, it seems that the system does sense the range of motion end points - probably by monitoring the motor and detecting when it stalls. (There is a DTC code for stalled motor.)
> 
> ...


I know it's a long time since you posted this but is there anyway you can specify where the HVAC control module fuse is? If the whole turning the cog wheel down solution doesn't fix it I'd like to take a look at your idea, and if not that, I've heard disconnecting the battery and waiting a bit fixed it for some people. Is that possible, and if so why? Would I need a new battery or.. 

Thanks!


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