Hi there I have that famous warm air driver/cold air passenger problem. I read the previous forums that said to replace the driver side blend door actuator, well I done that and it's still not working. I even pulled the fuse to reset the actuators like it states and still nothing. I'm at a loss of what else could be causing this. Could it possibly be the actual heater/ac control switches could be bad? I forgot to add that this is an 05 trailblazer ext with the slider controls for driver and passenger side heat/cool.
warm air driver/cold air passenger
- Thread starter mkoppler1234
- Start date
mkoppler1234 said:
There is actually only one blend door actuator, it just happens to be located on the drivers side but contols air flow on both sides.
There are tempurature actuators on both sides and could be one of those.
One way to test is to run the system on a low fan speed with the A/C on upper outlets, then check the air temp on each side. Increase fan speed while monitoring the driver side, If the sides stay significantly different no matter what fan speed, it probably is a temp actuator. If the drivers side gets warmer as you increase the fan speed, it could just be low on freon, should get that checked next.
When I was fixing my own AC problems (blown compressor and break in ac line), I noticed this exact behavior as I was refilling the freon. Once it got enough freon to start to cool, it would only cool on the passenger side, as I refilled the freon to the correct amount, both driver and passenger started working. Not saying you are low on freon, but it is one of the causes.
Not to steal this thread but i've noticed mine is alot different temps when using the defroster when the AC is off. Would that be the temp actuator?
mkoppler1234 said:
just a quick note. if you have dual climate control there is a tempature sensor for both passanger and driver sides. the passanger side is under the pannle by your left calf muscle, remove the pannel get your flash light and look for two wires going into the black box that channles the air. when you see the sensor turn the sensor to remove it. just so you know i have an 2002 chevrolet trailblazer ltz 4wd. the only reason i got that sensor was because my exterior temp sensor died and the dumba@% at lordco couldnt tell me which one was for the exterior sensor so i just bought both. they are pretty cheap i paid $11.42 for both of them with my discount at lordco. just sumthing that may or may not help you. keep in mind that if your passanger side is only blowing cold air when its on the hot air setting, then that tells me that when that sensor died you either had the ac on or it was pretty cold when it died. so the control modual is trying to read that sensor and all it gets is the lower temp on the passanger side so the modual thinks the passanger wants cold air and the driver wants hot air and thats what it will do. so a cheap little sensor could be your problem. for example : my exterior temp sensor was reading 13*ferinhit when it was actually like 30*ferinhit out side, so i replaced my exterior temp sensor and boom it works like a dream. just sumthing to think aboot.Good luck.
i just looked up that sensor part number for your truck and found this (part#W0133-1819019). this is the website it came from.
http://www.theautopartsshop.com/automatic-temperature-control-switch/oesw01331819019.html
but thats the sensor i was talking aboot. i know it says switch but when you copy and past in your browser youll see its not a switch its a sensor. and yes its for your 2005 trailblazer ext. hope this helps.
All vehicles in our platform have dual (driver's/passenger's side) temp controls. The manual ones have the sliders that the OP mentioned. The automatic/digital ones are the only system that have plenum temp sensors in the airflow in four places, a cabin ambient sensor near the driver's left shoulder, and the dome on the front of the dash has a sunload sensor to see which side of the vehicle is going to be heated up more by the sun. All to assist the algorithms in the control module to hold the driver and passenger more closely to their programmed temp.
The dome contains three light sensors. One on each side for the sun, and one facing forward to run the auto headlight/running light function. The rain sensor is a disk glued to the back of the windshield near the mirror, harnessed into the same wiring bundle as the mirror. It senses the sound made by drops hitting the glass, or the capacitive change in behavior when the glass gets wet - the shop manual doesn't discuss the technology and I don't have the system myself to investigate. (I also had my windshield replaced on my own $ after a desert sandstorm, and IIRC only OEM windshields can be bought with the special sensor area already prepared. Big $$$ for that puppy, and yes, for that, I'm too cheap. 
)
)the roadie said:The dome contains three light sensors. One on each side for the sun, and one facing forward to run the auto headlight/running light function. The rain sensor is a disk glued to the back of the windshield near the mirror, harnessed into the same wiring bundle as the mirror. It senses the sound made by drops hitting the glass, or the capacitive change in behavior when the glass gets wet - the shop manual doesn't discuss the technology and I don't have the system myself to investigate. (I also had my windshield replaced on my own $ after a desert sandstorm, and IIRC only OEM windshields can be bought with the special sensor area already prepared. Big $$$ for that puppy, and yes, for that, I'm too cheap.
You got the aftermarket rainsense windshield... Much much cheaper. Which is funny because the aftermarket one is not only wireless but it has two sensors and can even engage the windshield washers when the glass gets dirty....
The analog mammal behind the wheel 
No mysteries allowed here. Anything that bothers a member gets my interest, especially sensor and system questions.
Well ive gone through all the post and i cant figure it out i may be doing so.thing wrong and its quite frustrating. I changd an actuator the one under the glove box on the left blockwd by that bar. Nothing has changed im still getting that cold aor problem no heat what so ever comes through. Im trying to think but my brain is no good woth this typw of work. Please fellas winter is almost here and do t wanna take my kids out in the truck without peoper heat. And help is appriciated
2002 trailblazer slider controls
2002 trailblazer slider controls
Can you see the actuator's shaft move at all when you move the control? Does the shaft move when you pull and reinsert the fuse to force a recalibration?shadiBLebz said:
Your replacement actuator could be dead, the mechanical door could be internally jammed, or the control module or wiring could have a problem with that actuator.
No movement whrn i slide the control. The actuator ismt dead i plugged it in to the driver side and it worked fine. I dont know how to tell. With wiring i. No good with electrical
shadiBLebz said:
Im not sure if there is on the TB HVAC system but I have seen cases where the foam attached to the flap inside the duct comes loose and prohibits the flap from moving.
shadiBLebz said:
Take off the actuator and try moving the shaft on the door by hand and see if it is stuck or what... You should be able to tell if it is catching on something or moving alright.
I did do that, attempting to move the shaft by hand it would turn, im assuming the ammount needed. I did not feel it catching on amythong and actually felt loose. Is this normal, or should it be a little stiff as it was turning somthing?
shadiBLebz said:
That's about right, should go about a 1/4 turn AFAIK... Then there is no reason that the actuator wouldn't move it...
Ok then thats this weeks goal. Thanks for the insight ill be sure to get back to you guys when i make some headway
This sounds like a purely electrical problem. You need to cultivate a friend or buy some beer for somebody who knows how to read a schematic and who owns a voltmeter. We can post the relevant sections and talk an experienced person through the troubleshooting.shadiBLebz said:
Ok borrowed a testlight cause i lost mine, now i checked my wires and i got a ground and touched other wires from the plug should i have gotten a light on any of the others, i dont think i really know what im looking for
Without a full understanding of what a test light can do (apply voltage from one wire that could damage the place where your other wire goes), you're much better off leaving it out of the picture. Flailing about is not a troubleshooting technique. I posted what you need - an experienced person with a METER who can read schematics.shadiBLebz said:
Test lights are good for certain kinds of lamp and 12V accessory troubleshooting ONLY. Not electronic control systems like the HVAC actuators. They can do more harm than good.
Ok well that wasnt what i intended . When i go in to work tonight i wil enlist our shop mechanic he has all the tools i need they showed me the volmeter lastnight jist didnt have a chance to go in. Now what type of schematics should i show him and how dobi go about getting them?
C-ya
Member
- Aug 24, 2012
- 1,098
shadiBLebz said:
Mooseman's thread - http://gmtnation.com/f23/need-service-manuals-get-them-here-371/
Ok fellas im back. Couldnt get any friends with time to give me a hand. So i got a few tips from our shop mechanic at work i explained to him the issues ive been having. He told me to check the head unit were the sliders were and make sure it wasnt broken as the passenger side temp control was loose. In the process of taking off the plastic on the sliders i snapped the driver side slider...... i know flippin dumb. So i had to go looking for another found one on a envoy that looks the same. Put it in controls are fine except for if i put it on feet it blows to my face. Put it on face blows to feet and for defrost works and also blows to face.
Also i went back and opened up the temp actuator under the glove box. Unplugged it for 3 weeks hoping it would reset everything. Last week i plugged it back in and it started working turned over to the heat setting opening the door for hot/cold. Now i have heat all around .
Now my question is when i start the car to let it heat up ( -21 outside now) everything is ok but still blows a little cold on the passenger side until i drive for about 100meters. Is this normal? Or could there be another undelying issue?
And were i broke the slider could it be soddered back together i will attach a photo in a little bit.
Thank you all for your help
Also i went back and opened up the temp actuator under the glove box. Unplugged it for 3 weeks hoping it would reset everything. Last week i plugged it back in and it started working turned over to the heat setting opening the door for hot/cold. Now i have heat all around .
Now my question is when i start the car to let it heat up ( -21 outside now) everything is ok but still blows a little cold on the passenger side until i drive for about 100meters. Is this normal? Or could there be another undelying issue?
And were i broke the slider could it be soddered back together i will attach a photo in a little bit.
Thank you all for your help
shadiBLebz said:
if its -21 outside right now then yeah yeah thats normalfor it to be a bit cold for the first 100 meters or so. keep in mind our trucks use the heat from the engine to give you hot air. so as you drive the engine gets hotter which in turn will give you hotter air for the system. after the first 100 meters or so it should adjust with the airflow that cools the engine. the colder it is outside the longer it takes to heat up.
Denali n DOO
Member
- May 22, 2012
- 5,596
shadiBLebz said:
Regarding a sound I hear in mine. I was curious to ask you if, during all your playing around with the mode controls, temp controls and when you drive and hit the 100m and everything starts to work. Have you ever heard a single loud boom thud sound from the passanger floor area? A few of us are chasing this sound and I wonder if you may have experienced it at some point. HVAC ducting is something we think it may be but not sure. Thanks.
Denali n DOO said:
I cant say i have no. The only loud sound ive gotten recently was my rear wiper motor crappin the bed on me. Not sure what happened yet.
Sorry that i cant shed any light on that particular issue.
Ive read about this problem on the other thread, and ive noticed a few TBS in my neighborhood ill ask around.
shadiBLebz said:Any thoughts on wether the slider can be repaired?
i was doing sum thinkingn regarding that slider. are you able to post a picture so i can see it? but with out me seeing it all i can say is maybe sum epoxy unless its meatl then id recommend going to lordco or an auto parts store and see if they have any liquid steel. it comes in a small tube and its good for connecting brorken steel parts together on small projects. but with out the picture i cant be exact.
shadiBLebz said:
thanks for the pictures. id say if you have steady hands and a solder gun and solder try and resolder the pice back on. but id remove all the old solder off and then resolder it back together.if you dont have any of that then you next best thing would be to go to a junk yard and get a new one from there. keep in mind the junk yard my try and charge you full price for the part so call a stealership and ask how much it would be to get a new one, and theyll give you a price. then go to the junker.
i wish i had more info for you.