heat not working HVAC Blend door actuator

[KJS Sullivan]

Well, I finally have a situation where I need some help. I have a 2015 GMC Sierra Denali HD.

Today I noticed that my vents were blowing cold air after the truck had warmed up substantially. The temperature setting was at 75 degrees the air coming out  quite a bit cooler as it is 22 degrees outside today. I messed with the temperature the higher I went the cooler and higher the fan went. I set it to high maximum on both sides and finally blew hot air on the passenger side only.

I did a little research and found that it could be the actuator door on the driver side. Has anyone else had this problem? I'm sure there is  :-).

What is the best way about repairing this or confirming that it is the blend door actuator?

I can get into this thing I just need to know the steps to do it and I'm sure I can fix it.

Any help would be much appreciated.

Also, if there is a link to a place on this website or Tapatalk to review that would also be appreciated as I have done a search and could not locate anyting.

 

UPDATE  went out this morning start of the truck up everything worked normal. The blending of the vent system seem to work with a thermostat everything seems to be back to normal. And of course this makes me worried LOL when will it happen again? :-)

 

 

 

 

 

 

[PMurray]

Similar experience two days ago w/my 14 Sierra dble cab.  Issue cleared itself after manually adjusting temp and fan a couple of times.  Glad to not be searching for a repair (yet!).

[KJS Sullivan]

Mine did the same thing today everything works fine. Self-repairing vehicles I love it

[6_2LTZ]

Mine did this but it was no ac on drivers side. Would occasionally work on start up but fail after a short drive. Seems like many people are having this issue but I never saw someone post a fix other than take it to the dealer. I fixed mine by trading it in. 

[Badge767]

I haven't seen this behavior on my Silverado (she only has a bit over 1K miles on her ), but I do experience this every now and then on my 2005 Avalanche.

 

It may be apples and oranges, but my Avy also has dual zone temp controls similar to the Silverado. It is probably the blend actuator, as when it does occasionally happen, the air comes out in the correct place (defrost, upper vents, floor) depending on the setting, just not the correct temperature.Seems to only happen to me in warm weather, and the A/C continues to blow cold on the passenger side, but blows warm on driver side. With dual-zone temp controls, there's two blend doors.

 

The only "fix" for my Avy (if you want to call it that) is to shut off the engine and restart, and (knock on wood) that will clear the symptoms.

 

Intermittent issues can be a real PITA to nail down, you almost have to wait for a complete failure to diagnose.

 

Next time you experience it, try shutting engine off and immediately restarting to see if it clears itself...I'd be curious if the behavior is the same I've seen out of my Avy.

 

Good luck!

[KJS Sullivan]

14 minutes ago, Badge767 said:

I haven't seen this behavior on my Silverado (she only has a bit over 1K miles on her ), but I do experience this every now and then on my 2005 Avalanche.

 

It may be apples and oranges, but my Avy also has dual zone temp controls similar to the Silverado. It is probably the blend actuator, as when it does occasionally happen, the air comes out in the correct place (defrost, upper vents, floor) depending on the setting, just not the correct temperature.Seems to only happen to me in warm weather, and the A/C continues to blow cold on the passenger side, but blows warm on driver side. With dual-zone temp controls, there's two blend doors.

 

The only "fix" for my Avy (if you want to call it that) is to shut off the engine and restart, and (knock on wood) that will clear the symptoms.

 

Intermittent issues can be a real PITA to nail down, you almost have to wait for a complete failure to diagnose.

 

Next time you experience it, try shutting engine off and immediately restarting to see if it clears itself...I'd be curious if the behavior is the same I've seen out of my Avy.

 

Good luck!

I put mine in the garage the night . Took her out the next morning and everything was fine. First time it's happened and has not happened since. Little gremlins I think. Thanks for your input