Edmunds Answers

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  • avatar karjunkie 07/12/09 10:38 am PST

    The Chevy dual control HVAC system has a lot of problems like this. Usually it occurs right after a battery change or a jump start from a dead battery. I have read a lot of possible solutions. You may just need to reprogram the HVAC system. Try removing the HVAC fuses under the hood and in driver side fuse panel (between door and dash). Leave them out for 10 minutes. Reinstall fuses and start truck up. Place climate control on AUTO. The HVAC system should cycle through vents in calibrate mode. If the sytem does not reset to allow the proper control of each side, shut the control down with the power off button on bottom left side. Now see if both sides are responding to temp control changes. If this does not work, you can try some solutions that other owners claim have worked on their truck. Here is one procedure than several owners claim to have worked:


    1. Adjust the passenger side to full hot and the drivers side to full cold and put the system in AUTO mode.
    2. Turn off the ignition and turn it back on. In AUTO mode you will see the fan speed automatically adjusting up and down.
    3. Reverse the settings, drivers full hot (90 degrees) and the passenger full cold (60 degrees). Put it in AUTO mode and turn off the ignition and then back on.

    If this works for you, PLEASE come back and let us know as many Chevy and GMC truck owners are having this problem and we need to find a solution! Thanks and good luck!

Answers

  • fireman127 07/01/09 8:06 pm PST

    Have you found out what the problem was with your climate control? Mine is doing the same thing. I am about to buy another climate control unit to see if that is the problem. If that works I will let you know. Fireman127

  • saylorman 07/12/09 9:14 am PST

    My 04 Silverado just started blowing hot on the passanger side, but I can control the driver side. Will let you know as soon as I find a solution.

  • fireman127 07/12/09 9:30 am PST

    Well I too have changed the climate control to see if that was the problem and it did not change a thing. I also have a service 4wd warning now and have chaged that switch with no change. I am about to take it in to have them both checked. If I find an answer on either I will post it. I will never buy another Chevy again.

  • karjunkie 07/12/09 10:38 am PST

    The Chevy dual control HVAC system has a lot of problems like this. Usually it occurs right after a battery change or a jump start from a dead battery. I have read a lot of possible solutions. You may just need to reprogram the HVAC system. Try removing the HVAC fuses under the hood and in driver side fuse panel (between door and dash). Leave them out for 10 minutes. Reinstall fuses and start truck up. Place climate control on AUTO. The HVAC system should cycle through vents in calibrate mode. If the sytem does not reset to allow the proper control of each side, shut the control down with the power off button on bottom left side. Now see if both sides are responding to temp control changes. If this does not work, you can try some solutions that other owners claim have worked on their truck. Here is one procedure than several owners claim to have worked:


    1. Adjust the passenger side to full hot and the drivers side to full cold and put the system in AUTO mode.
    2. Turn off the ignition and turn it back on. In AUTO mode you will see the fan speed automatically adjusting up and down.
    3. Reverse the settings, drivers full hot (90 degrees) and the passenger full cold (60 degrees). Put it in AUTO mode and turn off the ignition and then back on.

    If this works for you, PLEASE come back and let us know as many Chevy and GMC truck owners are having this problem and we need to find a solution! Thanks and good luck!

  • fireman127 07/13/09 10:37 am PST

    Thanks fo trying. I have the manual climate control and not the digital, but I did try taking the fuses out and letiing it sit for 10 minutes and it didn't change a thing. If you here of any other ideas please let me know I would appreciate it thanks again
    TJ

  • saylorman 07/13/09 11:22 am PST

    I followed the procedure for resetting the system and now it blows hot on both sides and all the time.

  • fireman127 07/13/09 4:35 pm PST

    I am taking mine in next monday. I asked the tech and he thinks it is one of the door blenders thats not fuctioning. The 04 Chevys have 4 of them so he thinks one ore two of them are not functioning. I will let you all know if thats the remedy.

  • vmax150 07/24/09 11:09 pm PST

    I had the same problem on my 05 Suburban. I have changed the battery two times and the Climate Control issues occured each time. I have solved the problem on my vehicle by removing the negative cable from the battery and resetting the entire system. I had to remove and replace the cable two times to get the system to work properly (first time the hot and cold swapped sides - driver/passenger sides). Try this procedure, sounds to simple but it works.

  • yfrankiii 08/05/09 2:28 am PST

    I have 2005 Chevy silverado, same as GMC Sierra with dual climate control. I was getting hot air on drivers side but Passenger side was cold. I was also getting air only out of the defrost vents. I had to change battery for other reasons but noticed after I disconnect batteries, (2 for diesel) the air now worked in the front vents.....odd...but perhaps just needed to reset position on door flap but that only lasted a litte while and again had same problems. Anyways, took to dealer, said I need left side temperature door actuator and recirculation actuator per their trouble codes, wanted $290 for each actuator, each is the same part number. and another $460 for labor, over a thousand dollars. Researched internet and found someone had removed actuator and open it up, cleaned grease off the contact and circuit board and it worked for them. I figured worth a shot. I removed the actuator on the drivers side, right behind and above the gas pedal. I removed the actuator by removing two screws bottom and top. There is a backing plate or actuator plate that is a large half circle shape with small geared edge and two channels cut out in upper edge. Remove plate with actuator. Mark the location of actuator in reference to the plate. with actuator removed and unplugged i started engine and turned on AC. Move the white gear that was attached to the gearing on actator plate manually and see if cold air now flows to vents on drivers side. Mine did. I took apart actuator with small flat screwdrive and small pick to open clips on all sides. nothing springs apart. just remember how gears fit together, I removed gears and used q-tips and some alcohol to clean off contacts and board, You will see a split contact on black piece that backing plate locks into. Clean contacts and the bands they rub on. with gears out, i checked with 9 volt battery with small aligator cips to see if motor spins, reverse polarity to test both ways. Before you pop the cover back on, make sure the actuator fits into the backig plate in the same position. I had to take mine apart again because I didnt have the geas lined up to be in same position for alignment with backing plate. I have to slip gears out and move the black gear on tooth over so it lined up the same as before taking apart. Mine worked so I reassembled and re installed. INstallation is a pain. found with engine running and ac blowing i could move white gear on HVAC unit towards the back of car or and since its blwing the vaccum holds it in that position, same as the small knob to the front on the that needs to be pushed up to move another flap inside the HVAC unit. With those in place, put actuator plate back up against HVAC unit, one curved slot for where screw goes into a small tower hole and knob that you pushed up goes into outmost channel slot and white gear matches up to geared area on plate, Be careful, on back of white gear there is small knob that needs to slip into channel slot on backing actuator plate then press plate flatly against the HVAC unit. You can then slip on actuator unit into the spot that you marked previously to line up with backing plate. Screw in screws. Shut off engine prior to hooking up wiring. then restart and hopfully like mine...that wil work for you too. saved me a $1000....

  • chiefs1 07/31/10 11:50 am PST

    2005 GMC Sierra...Both sides were blowing hot air with AC on. After messing with the controls for a while, the driver side started blowing cold but the passenger side was still hot. With truck off I put both manual climate controls on hot and started the truck. The driver side blew hot and the passenger side cold, then the passenger side started blowing hot. Then I moved both down to cold while still running and both sides started blowing cold. It's like it wasn't lined up or calibrated. Not sure why that worked but it did. The problem started after I disconnected the battery to make an unrelated repair.

  • nick97 03/20/11 2:12 am PST

    under the dash above the hump on the floor there is a temp actuator that controls the temperature on the drivers side. easy to get to, cost two hundred sixty @ dealership or you can buy it from junk yard for forty bucks.

  • keithmarg 05/13/12 5:51 pm PST

    My 2005 2500HD Duramax was blowing hot out of the passenger side no matter what you adjusted on the controls. Drivers side was working fine. Not sure what caused it.... no battery was disconnected only thing I know that may have happened is that I had just connected our camper to the truck at a campsite while the camper was connected to the sites electrice (which i normally do not do) could have got some electric feedback to the trucks electrical system tho I am not sure. either way its now working fine thankfully

    Thanks karjunkie the following procedure worked for me.

    1. Adjust the passenger side to full hot and the drivers side to full cold and put the system in AUTO mode.
    2. Turn off the ignition and turn it back on. In AUTO mode you will see the fan speed automatically adjusting up and down.
    3. Reverse the settings, drivers full hot (90 degrees) and the passenger full cold (60 degrees). Put it in AUTO mode and turn off the ignition and then back on.

  • geno507 07/27/12 1:44 pm PST

    I have a 2008 Sierra 3500 with the dual climate control and had the truck in the body shop for a semi-minor LF collision repair. They had the battery disconnected. I turned on the a/c on the way home and had super hot air on the drivers side and cold on the passenger. Luckily I found this thread with everyones feedback. First I tried the battery disconnect..3 times to no avail. Then I tried this and it worked!!:
    1. Adjust the passenger side to full hot and the drivers side to full cold and put the system in AUTO mode.
    2. Turn off the ignition and turn it back on. In AUTO mode you will see the fan speed automatically adjusting up and down.
    3. Reverse the settings, drivers full hot (90 degrees) and the passenger full cold (60 degrees). Put it in AUTO mode and turn off the ignition and then back on.
    Thanks to everyone!! (now if I could only find a quick fix for my door lock acuators..(LF and RR)

  • rascals2 08/08/12 2:30 pm PST

    The answer that helped me was the adjusting the controls each way but, you have to let it cycle 1st or you confuse it!

  • duane777 09/17/12 2:07 pm PST

    chiefs1 answer above for manual controls worked great. I had to change a battery on my 2005 Silverado with dual manual climate controls and it began blowing hot on drivers side and clod on passengers. This happened while we were on vacation and was driving us crazy. Setting the controls on hot, then starting the engine,letting them stabilize and bringing them down did the trick. Back to normal!

  • Stever@Edmunds 04/01/13 1:12 pm PST

    You can reply in this thread by clicking the Answer this Question button and that will help keep all the information in one spot. Thanks!

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