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GMC Yukon AC and Heat Questions



  • gmcustsvcgmcustsvc Posts: 4,001
    Hello Bulldog26,
    Have you had anyone diagnose the problem with your vehicle? How long has the concern been present? Thank you,
    Mariah GM Customer Service
  • bcrawfo2bcrawfo2 Posts: 7
    My 2004 Yukon Denali has almost always had the hot on passenger on driver's side. I took it in and they "reprogrammed" it back in 2006. The problem still occurred. Figured they'd keep reprogramming every time, so I just lived with it.
    I could either just restart the car or turn the heat all the way up...then back down.
    I recently started reading about this problem and did the relearn (pull the fuse under the hood) and now I have hot air coming out of the defrost all the time. I've tried relearning a few times (by the way).
    Where do I go from here? I wouldn't think all my actuators went bad. Does that mean it's one of the control modules?
    I've put a call into the dealer and explained my case. I stated that I know I'm out of warranty, but it's a well known problem that I did report. I mostly don't want to pay for them to guess at things. Willing to pay to get it fixed...only if they fix it...and just what's wrong.

    Thanks for any thoughts.
  • AC/Heater control position has no effect. Constant defrost. Thank goodness the AC works in defrost at least. Is it a vacume line or faulty switch? Thanks for the help!!!
  • bcrawfo2bcrawfo2 Posts: 7
    After a long weekend and a 6 hour car ride the AC switch to blowing out the dash vents again.
    I'm still amazed that GM won't admit something is wrong here.
  • ilmk123ilmk123 Posts: 3
    The one you are looking for is under the dash ,right behind the consol and the start of the hump. You will need a 6mm or 7 mm. The mode actuator is located on the drivers side right above the gas pedal. Check out this link and it will help you. I have mine torn apart right now for the 3rd one........Scott +Actuator
  • bcrawfo2bcrawfo2 Posts: 7
    Thanks for the pictures. I wanted to try this but read a lot of the forums talking about taking the whole dash apart. I messed with this part one day investigating and couldn't get to that back screw out. I didn't try TOO hard.
    Strange question...
    Can I remove the actuator and move the door by for a few days (knowing that side will be stuck on cold) then wait for the replacement part?
  • ilmk123ilmk123 Posts: 3
    Yes that screw is a PITA. and yes you can. But at highway speeds tha door can change directions and start blowing hot air. I learned that one that hard way tonight. I heard if you get these at the dealer they are costly. You can get them on e-bay or parts store. Search that thread on how to calibrate them. You can e-mail me at
  • tidestertidester Posts: 10,110
    You can e-mail me ...

    Let's keep the discussion here so everyone can benefit. We ask that people not post email addresses in messages posted to our Forums. Thanks!

    tidester, host
    SUVs and Smart Shopper
  • bcrawfo2bcrawfo2 Posts: 7
    Thanks everyone....
    Wow...that was a PITA.
    Even getting the hush panel off was tough. That screw nearest the Who builds these things?
    The screws on the actuators seem to be 5.5mm, not 6. I was killing myself on the back with a 6mm. My socket set doesn't have a 5.5, but luckily a 7/32 if memory is right worked.

    I have my actuator out (52402588). Does anyone have a favorite cheap place to order, the right part?
    I saw another post (dang if I can't find the link) that said some of the replacement parts were mis-labelled and were for the wrong side. This would allow the door to swing once and then get stuck.

  • artaqqartaqq Posts: 6
    I have a 2005 Sierra Denali that I put a new battery in last night. This morning when i started it, all seemed well except the A/C was blowing out full heat. I parked the truck and disconnected and reconnected the battery. The Air kicked on and started working, then turned back to full heat. It's a 25 minute drive to work so, i just shut the climate controls off and drove in with the windows down a little. When I parked at work, I tried it again and it initially was blowing heat, then the A/C kicked in and it was back to normal. I don't know what to expect when i leave but, was wondering if this has happened to anyone else?
  • bcrawfo2bcrawfo2 Posts: 7
    This really is insane.
    If the the sales sticker on our trucks said "If you ever have to disconnect the battery, you will need to re-calibrate your climate control. If you fail to do that, you will likely cause permanent damage to a device deep behind the dash.", none of us would've bought these vehicles.
    But...strangely...that's the symptom we all have.

    OK....rant off.
    Supposedly when the AC system loses power (battery change)....the actuators that control air flow thru the AC system need to re-calibrate themselves. They do this by "hunting" the range of their movement. Move to one extreme until they can't any further....remember this position. Then move to the other extreme and repeat the process. I think sometimes that happens ok, but if for some reason it doesn't...the system will remember a bad limit and keep trying to have the actuator reach that unattainable position. Do that for a long period of time, you do permanent damage to that actuator. Now....when that actuator needs to be replaced, you have a $400-$500 service bill which involves removing the whole dash.

    There are procedures involving pulling the fuses or discharging the computer and then re-applying power and letting the AC system figure it out...I just don't get why that doesn't work right in the first place.
  • alnahdialnahdi Posts: 1
    I have Yukon 2007 SLT when I start the car the A/C start immediately and the temp is 74F fan on low although I had switched off the ac before and I changed the temp and the display changed to centigrades can any help meow have the same problem
  • Hello i have a 2000 or 2001 gmc yukon 5.3 this issue started roughly on & off 2 winter's ago.

    I have been reading e-mails, but not seeing my issue as bad as mine.

    It started in the winter 2 years ago, on & off all season & now for the last year it is continually blowing out wrong air. I would turn on the heat, and it would blow hot air for like 30 seconds, then it would turn to ICE COLD air coming out, then the summer after that( last summer) when i turn on the a/c it blows out HOT HOT air( could burn my hand if i kept it up to the vent). now like i said, when it first started, it was on & off, but now for the last yr it hasnt stopped 1 time! also, in the summer because it sooooo hot outside, i have to put the vents on defrost so the hot air will blow out up there & not on me, but even with the whole system off, it is still blowing HOT HOT air on me. I have to keep my ALL my front vents closed & it still blows it on my feet continually while i am driving.

    any input would be great!
  • artaqqartaqq Posts: 6
    Hi, Danielle.

    You might want to replace the AC fuse and see if that helps. My fuses were all fine but, I took them out and put them back in and the problem went away, so far. Someone commented here and said that sometimes you have to reset the heating and cooling system by replacing or just unplugging and re-inserting the fuses. Anyway, it seemed to work in my case. I had also unhooked and re connected my battery, since replacing the old battery seemed to trigger the problem in the first place. Best of luck to you. That's an unbearable problem to have.

    Let me know how you come out.
  • I have 99 Yukon that has a problem with the front air. The back air works fine. It has a new control unit in the dash. Compressor is working fine. Cold air is not coming out of the front vents. Would also like to know if there is any way to look at a service diagrahm of what's under the dash. We have had this vehicle to the dealership twice for air problems. First they charged it up and ran fine for a little while, then they put in control unit, which they charged us alot for. I'd like to be able to fix this myself. Any help is greatly appreciated. Thank you!
  • Air conditioning was working great. Was freezing. We did have to replace the condesor and the o rings but its been working great! Came home from shore on monday and now neither the front or rear air is cold its luke warm . What could it be ?
  • houndshounds Posts: 1
    For the past 4 months my AC was working at Setting number 5 only; Just last week the front A/c stopped working and now only the rear one works. I bought a new AC Heater control and installed it and it still doesn't work. Can someone please help with some advice? :mad: :cry:
  • Same on my 2000 Tahoe. Have been told to replace control panel but don't want to spend $400 on a new one and can't find a used one $100 close to where I live. However I have managed to unplug existing panel and reconnect. Worked for a couple months and has stopped working again. Sometimes it will work if I give the panel a good hit with my palm. Previously have changed blower and all relays and resistors. All points to Control panel.
  • I have the same problem. My AC blows fine for a short while before blowing hot on the driver side, still cold on the passenger side.
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