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Clicking noise under the dash, is it a Blend Door issue?

109K views 51 replies 22 participants last post by  lynst62 
#1 ·
Found this thread: http://www.impalaforums.com/chevy-i...-impala-lt-location-of-center-blend-door.html

Same sound, but my issue is just a little different. Instead of happening when you change the temp., it happens when you switch where the airs goes (i.e. from window defrost, to feet, to cabin). It has trouble moving the door so the air switches location...while it clicks the air is stuck blowing on the front window, but once it finally 'connects' and stops clicking the air is directed to the correct spot.

Is it the same part just in a different location?

2006 Impala SS
 
#2 ·
i have had 2 AC actuators go bad. Its likely one of those i would think. from my understanding the gearing is super cheap plastic and isnt too reliable. Not too sure if its same exact part but the actuator itself probably about $50. Super irritating problem hope you can get it fixed soon lol when mine had this it drove me crazy
 
#3 ·
Watch this, it'll show you how to do it yourself. You can find the part on ebay or you can get it from the dealer, the price difference shouldn't be that much.




I made this video so if you have any questions or need help, just ask either on here or on the comments section of the vid.
 
#4 ·
Watch this, it'll show you how to do it yourself. You can find the part on ebay or you can get it from the dealer, the price difference shouldn't be that much.

06+ Impala AC tick fix vid.wmv - YouTube


I made this video so if you have any questions or need help, just ask either on here or on the comments section of the vid.


So it IS the same part?? My clicking isn't connected the temperature wheel, but the air flow wheel. Or at least it seems that way...

Or does this noise ONLY come from this part?
 
#5 ·
No the temp has nothing to do with these, they are connected to the flow as you suspected. If you open your glove box all the way where it swings loose and turn your car on and play move the wheel to the defrost setting you'll see the blend door open or close.

As far as I know these are the only thing in the car that make this noise.
 
#7 ·
I have not change the air flow actuator yet so I am not sure how long it takes. On the passenger blend door it took me less than 10 minutes. I believe the air flow actuator is on the same side behind the glove box and would expect maybe 30 minutes to change.

On these cars I believe that the same actuator is used on the temp blend doors and recirculation air, and a different one is used on the air flow directional actuator.
 
#9 ·
I think you are seeing two different but related problems. There are four actuators in the split control system (ie, with separate temp controls for driver and passenger). Three of them are the same - one on each side, over the hump, and one behind the glove box on the right. The first two control the driver and passenger side blend doors, respectively. The one behind the glove box controls the recirc mechanism. These are the ones usually making the noise. I've replaced two of them now and somehow managed to repair the third one.

I think, if the video cited herein is the one I saw, it covers all three of these.

The fourth actuator is different. And a mutha to get at, according to the shop manual. Plus, looking at it, it's sort of a Rube Goldberg mechanism, which makes me wonder how it works. And, that may explain why it doesn't always work :)

Anyway, I notice that my vent controls get out of whack whenever one of the other three actuators has started making noise. I'm not sure how one affects the others, but there does appear to be a strong correlation between the two conditions. (I've got a couple theories on this, but it'll cost you a few beers to hear them :)

Resetting it - ie, disconnecting/reconnecting the battery - seems to solve the vent control issue once the other offending actuator has been replaced. Key point here, I doubt this actuator needs replacing. Fixing the noisy one and resetting the system is likely all that's needed.

The part numbers for the (three identical) actuators are GM# 15844096 or ACDelco # 15-73517. But, they've been superceded, and I think the new one is GM# is 22754988, but I can't verify that right now. I paid about 50 bucks for one at the dealer last week, and that's when I was informed of the new part number. Hopefully that means they've modified it to make it a little more reliable.

The reason I don't think it's the fourth actuator is because, when you change the vent settings, these things tend to go thru all sorts of gyrations, moving multiple actuators at the same time. For example, recirc is not allowed on some vent settings, so that actuator will move even though all you changed was the vent setting.

That said, I could be wrong. So, the best way to isolate is to get your hand on it when it's making the noise. You can feel which one is slipping. If it's one of the three identical ones, change it first and see if the problem goes away. Having to change the fourth one looks way involved (as in disassembling the dash). So if you don't have to do that, it will be a huge relief.

Hope this helps.

Doug

.
 
#12 ·
Eating my words....

m said:
Anyway, I notice that my vent controls get out of whack whenever one of the other three actuators has started making noise. (snip)

Resetting it - ie, disconnecting/reconnecting the battery - seems to solve the vent control issue once the other offending actuator has been replaced. Key point here, I doubt this actuator needs replacing. Fixing the noisy one and resetting the system is likely all that's needed.
Well, no sooner than I wrote that, I took the car to McDonald's for a cup of coffee and the vent selection was all screwed up despite the other three actuators working fine (ie, being noise free).

The car has a history of this, but it always seemed to correlate to one of the other actuators being in disrepair. And it comes and goes, eventually correcting itself.

One of my theories was that the incorrect vent selection was due to an electrical issue related to the failing actuator (noise propagating back to the microcontroller from the slipping actuator). The micro sits between the vent controls (ie, knobs) and directs the actuators accordingly. My thinking was that maybe the micro got confused and selected the wrong vents. For example, maybe the software was set up for multiple cars/vent systems and the noise caused a bit to flip somewhere thereby making the micro think it was controlling an 06 LeSabre instead of my 07 SS (hypothetically speaking).

Having only recently seen a pic of the fourth, vent actuator, my theory has shifted a little, with me wondering if it wasn't malfunction of the vent actuator rather than an electrical problem. Seeing the pic, it looks like the malfunction could indeed be mechanical instead of electrical. This thing appears to have some mechanical logic in it, 1890's technology


Anyway, for the fourth actuator, if it's not making noise, the worst scenrario is you have air coming out the wrong openings. This is most problematic in winter when only a trickle of air is getting to the glass. Fortunately, that doesn't present much of a problem here in north Texas, although a couple times last winter I was on the verge of taking the hairdryer out to the car


Seriously, this vent actuator looks like a booger to replace, so if it occasionally causes a problem you can live with, I'd try to ignore it. And, until I can tear into one, it's still not clear whether the incorrect vent selection is due to the actuator or the micro.

Doug

.
 
#13 ·
Well, no sooner than I wrote that, I took the car to McDonald's for a cup of coffee and the vent selection was all screwed up despite the other three actuators working fine (ie, being noise free).

The car has a history of this, but it always seemed to correlate to one of the other actuators being in disrepair. And it comes and goes, eventually correcting itself.

One of my theories was that the incorrect vent selection was due to an electrical issue related to the failing actuator (noise propagating back to the microcontroller from the slipping actuator). The micro sits between the vent controls (ie, knobs) and directs the actuators accordingly. My thinking was that maybe the micro got confused and selected the wrong vents. For example, maybe the software was set up for multiple cars/vent systems and the noise caused a bit to flip somewhere thereby making the micro think it was controlling an 06 LeSabre instead of my 07 SS (hypothetically speaking).

Having only recently seen a pic of the fourth, vent actuator, my theory has shifted a little, with me wondering if it wasn't malfunction of the vent actuator rather than an electrical problem. Seeing the pic, it looks like the malfunction could indeed be mechanical instead of electrical. This thing appears to have some mechanical logic in it, 1890's technology


Anyway, for the fourth actuator, if it's not making noise, the worst scenrario is you have air coming out the wrong openings. This is most problematic in winter when only a trickle of air is getting to the glass. Fortunately, that doesn't present much of a problem here in north Texas, although a couple times last winter I was on the verge of taking the hairdryer out to the car


Seriously, this vent actuator looks like a booger to replace, so if it occasionally causes a problem you can live with, I'd try to ignore it. And, until I can tear into one, it's still not clear whether the incorrect vent selection is due to the actuator or the micro.

Doug

.
I think this actuator is the one that's giving me problems. Joy:)
 
#19 ·
I may have same problem of where the sound is coming from. I'm getting a clicking thumping like noise from around the glove box. (After I start the car it starts going faster) I havn't had any issues with the air going in the wrong position. I'm thinking I'm having an electric problem. First mine just started two weeks ago. When I hit the breaks it quits but comes back then in about three mins it quits. Then another day hitting the breaks didn't do anything.. when i change air position it would go off at each new postion then start again.. then again it would quit after about three mins. Yesterday the only way to make it quit was to turn on the a/c it stop. Turn a/c off and back on again... leave along and it quits in about three mins. Today it started.. turn a/c on it didn't affect it.. turn a/c off it quit. Also now when I get out of the car it starts. Or if I come to the car and hit unlock on the key remote it starts before opening a door. I even walked outside a few mins later to carry things in and the doors were all shut motor off and it was still clicking. Even if you got the air on 0 it clicks. Talk about driving me crazy..
Anybody else having these issues??
Thanks
 
#22 ·
Finally got around to changing out the blend motor. Wasn't too hard actually. Spent probably 25 minutes total, with 10 of that messing with the glove box door:) Was trying to see if it came all the way off, when I decided I probably had enough room. The hardest part was trying to get the second screw back in after the swap. Couldn't see the hole. So far, no clicking!! :beer:
 
#23 ·
Is this still the issue if it happens when I have the car turned off and it still clicks when I set the alarm. It even happens when I do not have the air on or have the fan activated. Only way I can get it to stop is the turn the air on and turn the fan to the max setting and then it still makes the noise for about 45 seconds before it stops. When the car is started the noise starts off on the passenger side but then moves to the middle of the dash. Any help would be greatly appreciated.
 
#24 ·
Blend/Recir actuator replacement

Well I see this is an ongoing embarrasment for the chevy design engineers. Youtube shows this clicking or popping noise on just about every chevy model including trucks.

I've had 2 of mine unplugged now for 6 months on my 09 Impala. I tore into the driver side and spent hours trying to figure how to get at it. Finally gave up and unplugged the harness. Then the passenger side started clicking so I disconnected it as well. Now that Winter is moving in I need to get back to it since there is no heat.

I'd feel a lot better about it if I could smack the holy crap out one of those yuppie engineers that put this contraption together. I can just imagine what the newly designed 2014 Impala will be like. More of this stupidity which means you never want to keep one past the warranty period. :bang:

No video will be made on this repair, it's going to be real ugly.
 
#25 ·
Well I see this is an ongoing embarrasment for the chevy design engineers. Youtube shows this clicking or popping noise on just about every chevy model including trucks.

I've had 2 of mine unplugged now for 6 months on my 09 Impala. I tore into the driver side and spent hours trying to figure how to get at it. Finally gave up and unplugged the harness. Then the passenger side started clicking so I disconnected it as well. Now that Winter is moving in I need to get back to it since there is no heat.

I'd feel a lot better about it if I could smack the holy crap out one of those yuppie engineers that put this contraption together. I can just imagine what the newly designed 2014 Impala will be like. More of this stupidity which means you never want to keep one past the warranty period. :bang:

No video will be made on this repair, it's going to be real ugly.
You can add the engineer responsible for the battery placement to that list!!
 
#30 · (Edited)
I got mine fixed finally. It took several hundred trips in and out of the repair area under the glove box and under the steering wheel to replace the passenger side Air Recirculator Actuator and the driver side Air Temp Actuator. It was a truly good beer drinking experience.

I disconnected the POS battery terminal for the whole repair. Didn't try to reconnect till both actuators were replaced. Let it sit with the battery connected and key in run position for about 5 minutes. This allowed the relearn function to complete.

It is definitely a 5.5mm socket and the good fit was a blessing when trying to get the screws back in while in such a cramped position.

For the recirculator actuator I used a 1/4" Tee socket drive. There was only about 2 inches of clearance for the back screw. Actually the Tee drive and 5.5mm socket and a very short extension did the whole job.

The replacement actuators came from both Autozone and Advance Auto since the dealer had none in stock and wasn't sure which number was needed since the number on the bad actuator did not cross ref in his books. I thought that was very odd. :WTF: The Dorman 604-108 model for $36 is a perfect fit and is working fine so far.

Hope that helps you who are looking at this challenge. It's really a simple fix unless you are clostraphobic!:beer:
 
#31 ·
One quick note for others reading this, always disconnect the NEG battery terminal, not the POS. There is no difference as far as the electrical system is concerned, but when you disconnect the NEG, there is no risk of hitting the wrench on something and shorting out the battery through your hand.
 
#32 ·
:sign12:This is partially wrong and I will explain why.

If you disconnect the negative battery terminal what you have is +12V potential applied to all devices on the auto that do not go through the ign switch. So now lets say I have the neg battery terminal disconnected and I short the wires on the actuator with my wrench while replacing it. With +12V on one wire and the other now at ground potential from the wrench, I have possibly created a miniscule current spike that could destroy the IC circuits.

Either disconnect the positive terminal or both but DO NOT disconnect only the negative terminal.

Now when you jump a vehicle you should always go with negative terminals first to reduce the possibility of a spark and battery explosion.

I hope this clears up the age old myth about always disconnecting the negative battery terminal. :toothy9:
 
#34 ·
^ exactly, it's an open circuit, no amount of magic is going to change that.
 
#36 ·
Yes as in current flowing from the battery you are correct. The circuit is open. But in the event stray capacitance builds up and you short the terminals back to the circuit, snap. Some call this static electricity but in effect, with the negative bettery terminal disconnected you have created millions of capacitors at various parts of the electronics. :dizzy:
 
#37 ·
So... If I were to cut your arm off, and then touch something with it, you would still feel it? I don't think electricity works quite the way you are saying...
 
#38 ·
:giggle: No I don't mean that at all. And I can't say anything because I didn't believe it either till I learned the hard way. But ESD (electrostatic discharge) is very real when working with digital circuits and one of the best ways to prevent this from happening is to leave the ground circuits intact.

In fact if you check the Chevy service manual you'll see that the procedure includes removing the positive voltage source from the HVAC logic circuits. This actually serves 2 functions. It allows the logic memory to return to zero and keeps the the electrostatic build up at a minimum.

My first lesson was an expensive mother board in my home computer. I didn't feel a thing but I knew when I plugged it back that I had done damage.

Second was a computer in a 85 Voltswagen. About $800 unless your lucky enough to find one at the junk yard. This one I heard a faint snap when I touched one of the plug terminals with a screw driver, even with the negative battery terminal removed. This time I learned my lesson. ESD will cost you money! Keep the ground circuits intact if at all possible.
 
#39 ·
I see what you mean now, but thats not really a factor with jobs like this, only if you are going to be messing with fine circuitry. This is just to reset the system so the blend doors will learn their positions.
 
#40 ·
Blend door actuator on my car clicking

Thank you soooo much for this post..My issue is on a 2006 Impala SS V-8.. I just kick over at about 65,000 miles and the issues are about to begin. First I had replace the oil sensor switch now this little issue can drive you crazy:bang:.. But thanks to this forum:wav: I feel a sense of new relief.. I just joined this forum..I'm in southern California and I just celebrated my 59,000 mile birthday...

Thank guys...Be blessed
 
#44 · (Edited)
Another lesson learned is that when you get one working it then allows the other defect to start. These actuators are sequential so if one fails, the other that follow may fail as well.

Another lesson learned is if you don't have the 5.5mm socket, get it. It is so much easier when the socket holds the screw bolt secure while you position it during installation. Same goes for the very tiny ratchet or T-handle. Save you lots of time underneath.

Another lesson learned is to call the dealer parts manager and be nice. They can give you the part number for your model. There are 2 different models on most Impy's so you have the be sure which one you need. If you have to, dive under and unplug the one you suspect and then turn the ignition on to see if the noise stops.

Another lesson learned is the dealer manual does specify a re-calibrate after the replacement. The dealer computer hook-up will do this when they do the repair. So many mechanics don't even know this is happening. (Work around)--Carefully disconnect the battery using the positive lead first. Cover this lead with foam or something to insure it doesn't arc. Leave both leads disconnected thru the repair. Upon reconnecting the battery in the reverse sequence, immediately turn the key to on but don't start. Wait at least 3 minutes for the re-calibrate to occur before touching any knobs or switches.

Another lesson learned is these actuators are cheap. Buying a good one that is not dealer supplied is a crap shoot. If you have to replace the same actuator twice, go ahead and curse. You have that right. But when you feel better, dive under and do it again. You are still way under the cost of a dealer repair.

Another lesson learned, as mentioned before, always check the affected door for free movement in case it is jammed and make sure you are installing the new actuator exactly as the old one came out. Plan to spend at least 4 hours with occasional sanity breaks to complete the repair carefully and correctly.

Final lesson learned and this is a big one. Women's hands and fingers are usually smaller. If you just can not get the job done, promise the wifey (or BFF as it may be) a date and beg a little. She just may handle the problem for ya. Then when the job is finished keep your word to her and have a good time! Don't forget to brag on her at every opportunity.

Good luck!
 
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