Rear Heat?

Hello, I have a '22 RS. I'm assuming you're talking about the AC system/heat and not the heated seats. The controls to increase/decrease heat are located at the two inner vent ports positioned above the center stack. You turn the outer ring on the port left or right depending on how hot or cold you want the air. You should have fan speed adjustment buttons above your USB ports that are between the two AC ports and in your touch screen as indicated in my pic. I've taken a pic of the touchscreen that indicates all the controls you should have also. Be sure you've turned the AC system on and maybe check the "AUTO" and "SYNC" buttons in the menu. There are no controls for anything associated with the AC located in the rear. You'll just have the two vent ports and the ability to adjust the direction of air through them manually. I haven't checked for blowing air through those rear ports if you have the mode set to anything other than forward-blowing air. So, play with your mode settings and see if the air continuously blows with different mode settings. All of it is pretty straight forward so, if you're getting no air and you are missing actual buttons for controls, then you might take it in and have a dealer tell you what's going on.

If your vehicle was supposed to have heated front/rear seats and/or heated steering wheel, and you're waiting on chips, then you'll have the buttons for those items, but they won't activate until your chip modules are installed.

Let us know how this issue plays out. We're curious to know what happens.

petrock said:

Thanks for the reply. Yes, I'm talking about AC/heat system specifically for the rear of the truck. Not if the seats are heated. There is no problem with the air blowing through the front vents. Turning the dials and buttons does make it blow harder/softer & hotter/colder in the front. The problem I'm having is specifically with the vents for the back seats. No air comes out of them and the vents grills themselves are actually kind of cold to the touch even when I have the heat blasting in the front. I'm kind of wondering what the expected behavior should be. Should increasing the speed of the fans in the front also affect the speed of the air coming out of the vents in the back? Or are there separate control for the back vents? I'd like to figure out if I actually have a problem before taking it in. I'd rather not end up on an eposide of 'Customer States' because I am just 'Doing It Wrong'. Thanks again.

Click to expand...

Lol! I like the customer states thing. Seen many of those Youtube videos.

So, let's talk about the statement you made about turning the rings on the vents to make more or less airflow. Turning those rings do not make a difference in the amount of airflow you'll get from the vents. All you'll do is adjust the hot or cold of the air by turning those rings. The amount of airflow will be gauged from the buttons on the dash, up or down, and/or from the touch screen as indicated in my pic (the little fan icons). I believe that's what you were saying and already know that. Don't want to be redundant, but I do want to be sure and respond properly to your question(s).

As far as the air coming from the rear of the center stack console, there are no buttons in the touch screen, at the dash, or at those vents specifically that determine anything other than you moving those vents around to point them in another direction. So, no controls for those rear vents that create more airflow, or less heat, other than you cranking up the heat from the front of the rig and adjusting the airflow, which then should create more or less airflow from those rear vents.

If, in fact, you are getting zero airflow from those rear vents, it sounds to me that those specific vents have an obstruction or may be disconnected from the rest of the ducting system. Maybe one last effort before taking it in to have it looked at, and maybe you've done this already, is to look at the owner manual for any type of info that points to that specific part of the system. Probably won't find anything there that is schematic-specific. You can also Google the owner manual for the '21 Blazer, I think they are all the same in the HVAC area, and find a schematic that shows you the ductwork and the path it takes. Then you might be able to track it back to the dash and possibly find a way to check for any disconnection issues. Those ducts may travel through the center stack console to that location. Now, I know this could turn into a deep rabbit hole to hell doing this yourself, so you might want to take it to the dealer and ask them what they think, and then do the inevitable... ask for a quote. I shiver when saying that.

I assume you're still under factory warranty? You may need to exercise that option.

* I went and tested all the Mode settings to see how it affected the airflow on those rear vents. If you have just the Forward Mode (Face) on, fresh air, or recycled air, the airflow is the most prominent, and strongest, and increases considerably with each click of the button in the rear. If you have the floor vents and the forward (Face) vents engaged together, then the airflow will be decreased to some degree on those back vents. The same applies if you add any other Mode to the forward Mode. The airflow decreased to some degree on the rear vents. If you disable the forward Mode and just use defrost, floor, or anything else but eliminate the forward air vent, then you will have no airflow to the rear vents. The only way to get airflow to the rear vents is to be sure and have the forward (Face) airflow engaged. Just defrost... no rear airflow happens. Just floor venting... no rear airflow happens. Forward Face vents with any of those other options included... airflow happens in the rear.

Don't know if this has anything to do with your issue, but there it is.