Climate control reset instructions.

[Rossum Possum]

Just learned that a lot of GM trucks with dual zone climate control have had issues with their blend door actuators for the AC system.  A blend door is what regulates the temperature of the air leaving the vents.  They can either be vacuum or electrically operated.  A clue to this may be that the temperature on one side may not match the other side (hot, or warm when it is set to cold).  I was fighting an issue with my AC just not blowing very cold at all, and I feared the worst.  But, I noticed on my way to work that the window and windshield on my passenger side were fogging up from the cold air.  You just never think to check the passenger air coming out.  I was able to reset the AC by disconnecting the truck’s battery for 30 minutes, reconnecting it, then turn the key to on, but do NOT start the engine.  During this time, do NOT touch anything!  Wait for approximately 1 minute, the truck will tell you to roll down the driver’s window, then back up.  After 1 minute, turn the engine on.  The AC system has reset itself, and should function as normal.

[2speedbump]

I think somewhere in that routine for it to work properly you have to pat your head and rub your stomach rapidly for 30 seconds.

 

[Ed S]

On 9/12/2020 at 11:04 AM, Rossum Possum said:

Just learned that a lot of GM trucks with dual zone climate control have had issues with their blend door actuators for the AC system.  A blend door is what regulates the temperature of the air leaving the vents.  They can either be vacuum or electrically operated.  A clue to this may be that the temperature on one side may not match the other side (hot, or warm when it is set to cold).  I was fighting an issue with my AC just not blowing very cold at all, and I feared the worst.  But, I noticed on my way to work that the window and windshield on my passenger side were fogging up from the cold air.  You just never think to check the passenger air coming out.  I was able to reset the AC by disconnecting the truck’s battery for 30 minutes, reconnecting it, then turn the key to on, but do NOT start the engine.  During this time, do NOT touch anything!  Wait for approximately 1 minute, the truck will tell you to roll down the driver’s window, then back up.  After 1 minute, turn the engine on.  The AC system has reset itself, and should function as normal.

What year, model is your truck? My 14 Sierra has a bad drivers side vent actuator. Blows hot air out drivers vents when A/C is on. Passenger side works great. I just took it to dealer 2 weeks ago. Told me actuator is bad. I use to reset the system like you said and it usually made it work correctly for a few days but eventually it stopped helping the issue. Dealer wants $900.00 to replace actuator. Was $90.00 to just diagnose.

[Rossum Possum]

58 minutes ago, Ed S said:

What year, model is your truck? My 14 Sierra has a bad drivers side vent actuator. Blows hot air out drivers vents when A/C is on. Passenger side works great. I just took it to dealer 2 weeks ago. Told me actuator is bad. I use to reset the system like you said and it usually made it work correctly for a few days but eventually it stopped helping the issue. Dealer wants $900.00 to replace actuator. Was $90.00 to just diagnose.

Ed, my truck is also a 14.  If the actuator is truly bad, you can change it yourself if you have some mechanical knowledge.  I believe GM calls to remove the entire dash, but I did see a video on YouTube where you only removed the glovebox and radio.  I’ll see if I can find the link,

[Ed S]

4 minutes ago, Rossum Possum said:

Ed, my truck is also a 14.  If the actuator is truly bad, you can change it yourself if you have some mechanical knowledge.  I believe GM calls to remove the entire dash, but I did see a video on YouTube where you only removed the glovebox and radio.  I’ll see if I can find the link,

I have seen that video. It's a little over a minute long. I understandhow to do it. i am somewhat of a mechanic so not afraid to do it. Just looks like a pain in the a** to do. Ha. Thanks for your comment though about it. I'll probably just do that next spring since summer is about over here in Iowa now.