Climate Controls

[Jacoby]

Maybe Im going crazy I don't know.  I got a 17 Silverado with 14000 miles on it that I bought used with 9000 miles on it.  I still consider that pretty new.  So Im perplexed by what Im experiencing and would be very shocked if something was already wrong with the truck.

 

So heres whats happening.  When I push the defrost button im only getting air out of the two side vents for the windows and air at my feet, no air out of the top vent to "defrost".  If I press the defrost/foot button there is no change, still no air out of the top vent.  During this there is a loud hiss out of the top vent as if its closed.

If I push the foot button like I wanted to just run the heat then all of the sudden the top vent opens and I get a bunch of air out of the top vent like the defrost is all of the sudden working. 

Ive also noticed that when I push the foot button for heat the AC compressor kicks on.  When I run just the defrost setting the AC compressor never comes on. 

 

AC to cool and all the front vents work as they should

 

Now am I crazy or are my climate controls outta whack. 

 

 

[silveradosid]

as per usual with these trucks disconnect the battery to let everything reset

[xMEATxHAMMERx]

Does the radio display a climate change when switching between the 2 defrost buttons? Do you hear it try to switch positions? If yes for either of them, I would check the flapper and the connecting linkage. If no, it could be the head unit or the dash switch.

And as always... Enjoy your ride!

Sent from my SM-G955U using Tapatalk

[Jacoby]

6 hours ago, xMEATxHAMMERx said:

Does the radio display a climate change when switching between the 2 defrost buttons? Do you hear it try to switch positions? If yes for either of them, I would check the flapper and the connecting linkage. If no, it could be the head unit or the dash switch.

And as always... Enjoy your ride!

Sent from my SM-G955U using Tapatalk
 

Yes the display changes and yes I can hear it try to switch.  The top vent opens when I switch it from defrost to the low vent setting.  I guess its the buttons or the head unit as you suggest.  Ugh I guess its gonna be a trip to the dealer

[xMEATxHAMMERx]

It may not be the button, if the door is partially switching, it may be obstructed. Under warranty, go to the dealer... Not under warranty, I would try to gain access to the door and make sure that 1) there is no debri in there. Some vehicles don't come with cabin air filters, which allow crab to get in there. 2) make sure no critter made a home out of your truck. That's where I would start at least.

And as always... Enjoy your ride!

Sent from my SM-G955U using Tapatalk

[Sierra Dan]

One other possibility could be a plugged Cabin Air filter.

Have you looked at yours or changed it since purchased?

My Wife's Altima was doing just as you describe and a new cabin air filter solved that issue.

Instead of a hissing though.... the sounds was more of a flutter or vibration.