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Chevy TrailBlazer Climate Control Questions



  • gorilla2gorilla2 Posts: 1
    has their been a issue with the fan speed controls? is their a resistor pack? i have a 2004 with only 2 thru 4 working.
  • traveler73traveler73 Posts: 5
    when air is on condensation leaks all over floor from underneath dash ---has anybody had this happen/ know what it is?????--thanks!
  • lrs1018lrs1018 Posts: 2
    I opened glove box and i see nothing but fan motor. How do i pull radio and control modulator out because i see no actuators to spray any wd40 onto, ( where are the vent flappers) this all sounded easy till i opened glove box and looked inside.
  • jerrcribjerrcrib Posts: 21
    drop glove box to floor look to your left under dash just spray the wd 40 into this area it will coat everything,it will not hurt electrical components. You will not be able to see what you are doing. First actuator is to your immediate left. To change control modulator you will have to remove all the trim from front of dash,it is all one piece,it is really not that hard to do, You can the get to modulator radio speedometer cluster. To get to middleactuator,etc. you will have to pull completetop of dash out. I would not recommend you doing this.If i can help you more let me know. Jerry
  • jerrcribjerrcrib Posts: 21
    control modulator gm has always had a problem with this, no way to repair different components, all one piece about 160.00 from ac delco gm parts on line
  • cjoyce01cjoyce01 Posts: 2
    My a/c has been running cold but only for about 30-40 minutes and then the air blows warm. I don't know if this is a normal service issue or does it mean there could be a leak? There's nothing in the owners manual for servcing the a/c.
  • jerrcribjerrcrib Posts: 21
    something is cutting out power to the a/c clutch,clutch sensor switch or low pressure switch. check freon first but if it cools for that long I would say the freon is okay no leak. I have a 2002 trailblazer and have had this problem off and on for 7 years dealer never found the problem under warranty. The next time it quitscooling pull over cut engine off and start up again to see if it starts cooling again. jerry
  • cjoyce01cjoyce01 Posts: 2
    Thanks Jerry! I'm going to a dealer tomorrow but I don't want them running up my bill for stuff I don't need, i.e. freon. I'll try your suggestion. At least I feel armed with knowledge for tomorrow. Thanks again!
  • shutterbshutterb Posts: 1
    Where is this sensor and what does it look like? I see a small two wire sensor just in front of the radiator. is that it?
  • pa2tx2mdpa2tx2md Posts: 1
    I am having the same problem with my 2003 trailblazer. The external temperature reading fluctuates, starting out at 50 degrees and staying there until it eventually corrects itself. Then it may go back to 50 degrees. The internal air comes on full blast as the external temperature reading rises rapidly to read the actual outside temperature. Did replacing the ambiet outside temperature sensor resolve the problem. Is it something that a dealer has to do or is it a relative simple fix? Where is the part located?
  • burdawgburdawg Posts: 1,524
    The easiest way to replace the ambient sensor is to remove the grill. It's mounted under the top radiator frame rail, a little hard to see, but if you follow the wires you'll find it. You have to push the plastic snaps back to get it out of the hole. I went to the dealer for the new part, the earlier style has been discontinued and replaced by the later style, but it's the same part on a plastic bracket. You remove the sensor from the bracket, throw the bracket away, and push the new part into the existing hole (it just snaps in).
  • aopimeraopimer Posts: 5
    My trailblazer is doing the same thing. Do you know the part #? Is this something that has to be purchased through a chevy dealer?
  • aopimeraopimer Posts: 5
    Do you know the part number of this sensor? It is way too hot to be dealing with no a/c. Thanks.
  • jerrcribjerrcrib Posts: 21
    no I do not know the # I have not had to change mine
  • aopimeraopimer Posts: 5
    I've replaced the ambient sensor, but it's still reading in the 40's & 50's when it's 90 degrees outside. Any ideas? Please help! :confuse:
  • james107james107 Posts: 3
    Found a fix yet?? I have the same issue with my 02 Trailblazer. Replaced the sensor, still reads at 50 degrees. One odd thing, while going to get the new sensor, I just left old one hang, and it worked for about 20 minutes then nothing again.... Even after new one put in, still nothing.
    Let me know if you found the cure, drop me an email even at

    Thanks. Jim
  • aopimeraopimer Posts: 5
    Mine was working off and on for a few months. I finally bought the new sensor. When I replaced the sensor, nothing changed for about 1 1/2 days. It still continued reading 50 degrees and sometimes lower. After that, it has worked without a problem. I don't know if the computer had to reset, but it works now.
  • james107james107 Posts: 3
    Thanks much for the info. I put the new one in, but didn't wait very long for results, and took it back out an returned it, as was 22 bucks, but am going back an get it, and plug it in and give it a chance.

    Thanks again, jim in Ohio.
  • burdawgburdawg Posts: 1,524
    That sensor is nothing more than a thermister. Consequently any resistance in the contacts in the connector will affect it's accuracy. Make sure there's no corrosion, dirt or other contaminents in the connector.
  • james107james107 Posts: 3
    I figured it must be some sort of variable resistor, and am guessing it is accross the ground line, thus do not see power at the connector.
    I did spray it with contact cleaner, but am going to double check again when i get the new part, which is tomorrow, takes 3 days to order an get it in at Auto Zone.

    Thanks Jim, Ohio
  • it started when the check engine light came on and i took my tb to have it checked by computer to see what was wrong, the guy put the computer on and it blew a fuse so he replaced the blowed fuse and said it was an oxygen senssor, so i replaced that, then resset the service engine light, but now i am faced with another problem HOT AIR, no matter what setting you turn it on it blows hot air from my vents, even in the off postion it blows hot air, does anyone know what is going on ?? plz help
  • it started when my service engine light came on and i took it to advance to have them put the computer on to see what was wrong the guy there put it on and said his machine was messed up but he blew a fuse in the meanwhile, i replaced fuse and on the way home i started noticing the hot air, on every setting even ac and on the off position hot air was blowing, the ac and vents all worked fine before this, so i thought it might be do to the malfunction, so i took it to another place and they fixed the service engine light it was a oxygen sensor, so i figure problem solved , WRONG, hot air still coming from all vents even when they are off a/c compressor working fine but it also blows hot air,and if i leave the vehicle running for a while with the ac on it dies, why is heat coming from everywhere???
  • ck all your fuses. sounds as if relay or fuse for ac is bblown
  • When my TB a/c started acting strange, the external temp would go down usually to around 50 degrees, but sometimes it would go down to -35 degrees and the computer would tell me that ice was possible. All of this caused hot air to blow b/c the TB's computer thought the heat should be on. I bought a new ambient outside sensor for about $20.00 from the Chevy dealership part's department. Then I looked on line to see where the sensor was located and how to change it. It was pretty easy to change. It then took about 2 days after that for the a/c to work properly again. I don't know if the computer had to reset or what, but it now works great, just like new. Hope this helps.
  • i dont think its is that , because i unhooked the a/c completely and still gettin g the hot air, someone told me it wasnt the heater but the heat was comming directly from the egine, so i will prob have to pay the 300 to get it looked at , tanks for the reply
  • I have had my 02 TB LTZ at the Chevrolet dealership for 6 months now. They have changed every part that must be related to the a/c. Please see forum " 2002 TB AC Compressor problems" with attention to post 15-19. I have described all my dealings with GM and am now starting over with a new dealership at the "field engineers" request. Surprise!! They have started with the outside temp sensor and wiring, just as the other dealership did 6 months ago. This whole ordeal is just unbelievable. GM tells me they have had no other complaints about this problem. After reading how many others have had the same problem, I am wondering how many of you called "Chevrolet customer service"? I'm thinking there has to be more than me who has called to report this problem. They say NOT. Hmmm?
  • i called gm and they said that i was the frist to complain and had know other ones like this and said to take to dealer and let them check it and then if they find something they might pay for it but there was know guarantee that they would pay to repair it and that i had to pay for the dealer to put the machine on itmy trailblazer has very low mileage on it and they said they didnt care please let me know if they find the problem because mine is still not working right i have to run it for a3miles when it is cold before defoster will come on or let it idle for about 20 to 25 mins before it will work
  • I called GM customer service after my TB had been in the dealership since July 1,2008. I explained what it had been doing and the dealership has assured me they contacted technical service and did everything they told them to do, but it still did not correct the problem. I did pay for the first repair, which was changing the outside sensor and wiring. I picked it up and about a week later, the same problem. From that time on , the dealership stayed in touch with GM tech support to try what they thought would fix it. Nothing did. Part after part was changed. I left the car there and checked in on it from time to time. They had no problem duplicating the problem, they just couldn't find the problem. In November, when I contacted customer service myself, they just couldn't believe my TB had been in the dealership for that long and not been fixed. It was not under warranty, it had expired by 2 months when the problem first came up. Like I said the outside temp went to -17 on a day when it was 98 outside. It then went up to 50. Of course the heater came on. When I picked up speed on the interstate, it would come back up to the real outside temp an start working. But, this was an off and on thing. Customer service has been in touch with the "field engineer" that was assigned to the case. Between the tech support and field engineer, they decided I should bring my TB to a different dealership, which they felt was more "qualifed" in the A/C dept. I did just that, but they told me it was the outside sensor and wiring, just like the previous dealership first told me in July of 08. I picked it up today and I still have my doubts about the A/C. Of course, it was way to cold to check the A/C to see if it would work correctly in the AUTO mode. I will have towait for warmer weather. I did not have to pay anything at all. They felt bad that it has been in dealership for over 6 months and no one could repair their automobile. Like I say, I paid the first time , but since that was not the problem, I have not paid for anything since that time. Why should I pay for parts or labor when they can't repair it? G. M has agreed with me and apologized the I have been with out a vehicle all this time. I mean I have not had it at all in 6 months. I did not bring it home for a day or two and bring it back. Everytime they replaced a part, they would test drive it and see for themselves it was not fixed. I was lucky enough to have an extra vehicle to drive. They did not supply me with a "loaner". I do not feel it has been repaired, but agreed to take it and try for a couple of weeks until the weather warms. I have seen many postings about this climate control problem with false readings for outside. I have told GM and both dealerships about it and they have told me they do not know of anyone else with the problem and told me I was a "one of kind" problem. I copied some of the postings and sent it in to them. I also told them to go online as I did and they would see it was quite common. Either they haven't checked or don't want to admit it is a big problem. At this point, I have paid no more and will wait a while longer. We will see........
  • mlehmltnmlehmltn Posts: 1
    I have a 2003 trailblazer that has decided to only blow cold air on the driver's side and hot air on the passenger side. This is timely as we are preparing for a 1800 mile round trip this coming week. Has anyone had this problem and been able to fix it?
  • nremtp415nremtp415 Posts: 1
    I have experienced the same problem, no air out of the dash vents. I replaced the mode actuator located between the instrument stack and the glove box (had to use a come-along to pull a dash support over a hair to get the old one out and the new one in) and the control module (apparently only controls the fan) to no effect. I also tried the WD40 trick. There must be at least one more mode actuator somewhere in there? Does anyone know where it is and how to get to it?
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