Strange HVAC issue since windshield replacement

[LeeStafford11]

Here's a new one for me. I had my MY windshield replaced this past Tuesday (OEM glass, 3rd party installer) and when I was driving to work on Wednesday morning the AC, which I always keep on "auto" at 68°, decided that it only wanted the air to come out of the windshield and foot vents. It just switched on it's own. When I got to work I rebooted the car. On my drive home everything seemed OK. Again this morning when driving to work, the "auto" setting just changed the vents from dashboard to windshield/feet on it's own. I can only get the dash vents to work on manual mode after it switches.

Did the windshield installers forget to reconnect something? Or did they move/adjust/break something? This is a very weird problem and I'm not sure why when I am driving home (outside temps >90-100°) there's not issue but when going to work (outside temps ~75-85°) it does this switch. My software is on 2021.24.3 currently. I expect the 24.4 update any time now.

I have an open service appointment but it's nearly a month out. Just wondering if any of you all have any ideas.

thank you

 

[Darblish]

You might have some condensation or debris in front of the cameras behind the windshield. I think that’s how the car decides whether it needs the defogger or not.

 

[alexcue]

Here's a new one for me. I had my MY windshield replaced this past Tuesday (OEM glass, 3rd party installer) and when I was driving to work on Wednesday morning the AC, which I always keep on "auto" at 68°, decided that it only wanted the air to come out of the windshield and foot vents. It just switched on it's own. When I got to work I rebooted the car. On my drive home everything seemed OK. Again this morning when driving to work, the "auto" setting just changed the vents from dashboard to windshield/feet on it's own. I can only get the dash vents to work on manual mode after it switches.

Did the windshield installers forget to reconnect something? Or did they move/adjust/break something? This is a very weird problem and I'm not sure why when I am driving home (outside temps >90-100°) there's not issue but when going to work (outside temps ~75-85°) it does this switch. My software is on 2021.24.3 currently. I expect the 24.4 update any time now.

I have an open service appointment but it's nearly a month out. Just wondering if any of you all have any ideas.

thank you

I had my window replaced also, in the morning it's blowing on the window also first. As the day heats up it's coming out of the dash when i use it. It will switch automatically to widow which makes it hot. I had the windshield replaced two days ago, and it is driving me nuts. I have to go in manually and switch it to dash to really cool off.

In the morning it's been warm say 68, so there shouldn't be any condensation, but I'll keep an eye on it. Even as it warms up it still comes up in window, as it even causes condensation there from the cold air. I'm on 24.4 now. I'm trying to recalibrate myself.

 

[Axoss2]

I have this exact same problem. I just got mine back today from a windshield replacement as well.

 

[Axoss2]

I have this exact same problem. I just got mine back today from a windshield replacement as well.

I had my done at a Tesla service center with OEM glass.

 

[Axoss2]

I have this exact same problem. I just got mine back today from a windshield replacement as well.

I had my done at a Tesla service center with OEM glass.

Ok, I can't figure out how to edit or delete my post so I just have to reply to my own post. :-/

I have a 2021 Model 3 and I had my windshield replaced with OEM by Tesla at the Houston Service center. I received it back today. Unlike OP, I can't get my AC on Auto to do anything but the front windshield. Even in my garage where it's cool it still only blows on the front windshield. I've rebooted the software twice but it did not help.

Does anyone have any idea of what I try? I already put in a service request but I'd hate to have to go back to the service center. It's about a 200 mile round trip for me.

 

[alexcue]

Let us know what they say… or maybe it’ll be updated with firmware.

 

[OCJeff]

Ok, I can't figure out how to edit or delete my post so I just have to reply to my own post. :-/

I have a 2021 Model 3 and I had my windshield replaced with OEM by Tesla at the Houston Service center. I received it back today. Unlike OP, I can't get my AC on Auto to do anything but the front windshield. Even in my garage where it's cool it still only blows on the front windshield. I've rebooted the software twice but it did not help.

Does anyone have any idea of what I try? I already put in a service request but I'd hate to have to go back to the service center. It's about a 200 mile round trip for me.

Just FYI…. You need 6 posts to be able to edit/delete posts.

 

[EVer Hopeful]

You might have some condensation or debris in front of the cameras behind the windshield. I think that’s how the car decides whether it needs the defogger or not.

I would hope they did a camera recalibration as part of the installation, and if they did this wouldn't be a problem

 

[EVer Hopeful]

I had my done at a Tesla service center with OEM glass.

It's *possible* that they farmed this out

I had to replace the windshield in my PriusV and one dealership said they would do themselves, but the others all said that they farmed it out to Safelite ... which is where I eventually got it done

I have no idea what Tesla does, but I figured that if Toyota farms it out, then maybe some special equipment is used and they wouldn't get enough appointments to justify the cost of ownership

 

[LeeStafford11]

I would hope they did a camera recalibration as part of the installation, and if they did this wouldn't be a problem

They did not do a re-calibration due to the fact we can just select a re-calibration from the touchscreen and let it do it over 5-25 miles. I did that right away and it did not prevent this from happening unfortunately.

My car updated with the 24.4 yesterday and maybe it will affect change on this? Confidence is not high though. I drove home yesterday afternoon w/o issue and this morning I was able to drive to work w/o any issues but the temp difference between my garage (100°) and the outside (91°) possibly made it so there was no condensation? We are supposed to have lower temps and rain next week. I will see if this makes it fail again.

if it does turn out to be condensation, what was the reason it did not happen with the original windshield or my first replacement last April? (I'm on my 3rd one due to 60m+ freeway r/t every weekeday... damn AZ roads)

 

[EVer Hopeful]

They did not do a re-calibration due to the fact we can just select a re-calibration from the touchscreen and let it do it over 5-25 miles.

interesting. I didn't know that . . .


. . . due to the fact that I STILL haven't got my car yet

 

[Axoss2]

I have a 2021 Model 3 and I had my windshield replaced with OEM by Tesla at the Houston Service center. I received it back today. Unlike OP, I can't get my AC on Auto to do anything but the front windshield. Even in my garage where it's cool it still only blows on the front windshield. I've rebooted the software twice but it did not help.

A remote technician called me and gave me tests to do. He asked me to take photos of the windshield camera assembly from the outside and send them to him. He also asked that I run the AC in Auto and send a message of the time I started running the AC. This way, someone could analyze the data from the car to see why it will only blow onto the front windshield in Auto mode.

He informed me that the windshield assembly comes as one piece that gets screwed into the car body at the shop. He said if the windshield is misaligned it was most likely a manufacturing error of the windshield. The techs that install it don't have much control of the alignment, according to him.

He also informed me if there are any fingerprints or debris on the cameras on the inside of the windshield it could cause this issue. This is why he wanted to see the photos of the camera. He also asked me to look myself to see if I could see any. I did not see anything like that on the camera lenses.

So, they are still looking into it. I have to wait another 3 weeks to get it back to the shop.

 

[Axoss2]

I have a 2021 Model 3 and I had my windshield replaced with OEM by Tesla at the Houston Service center. I received it back today. Unlike OP, I can't get my AC on Auto to do anything but the front windshield. Even in my garage where it's cool it still only blows on the front windshield. I've rebooted the software twice but it did not help.

Update 2021.24.4 fixed it!

2021.24.4 came to my car this afternoon. When I came back to my car from the evening the AC on Auto works like normal again. I still can’t believe. I honestly thought they had botched something with the windshield or camera when doing the reinstall.

Now I feel like a jerk because I really tore into to them about it. Maybe I should send them some flowers or something…

 

[rrsurfer1]

Update 2021.24.4 fixed it!

2021.24.4 came to my car this afternoon. When I came back to my car from the evening the AC on Auto works like normal again. I still can’t believe. I honestly thought they had botched something with the windshield or camera when doing the reinstall.

Now I feel like a jerk because I really tore into to them about it. Maybe I should send them some flowers or something…

Mine is doing this too, also just got windshield replaced. I'm on 24.3 ... Wondering if I should keep my service appointment or wait for 24.4...

 

[Axoss2]

Mine is doing this too, also just got windshield replaced. I'm on 24.3 ... Wondering if I should keep my service appointment or wait for 24.4...

Message in your service appointment that you have seen others with this issue are having it resolved with 24.4. They can pass it to a software tech who may be able to trigger the update on your car. Not sure but worth a shot! That way you can know sooner if 24.4 will fix it and if to keep your appointment or not.

 

[LeeStafford11]

I had the windshield installer stop by and take a peek at all of the connections that they must disconnect and reconnect and everything seems in order. I've not had the HVAC issue for the past few days so maybe the 24.4 s/w helped with the issue or just the deep reboot that a s/w update does once it's installed helped. Unsure at this time but I did cancel by service appt for the time being. It' supposed to be rainy and humid later this week here so I'll see if it reoccurs. Thank you for all your answers.

 

[Transformer]

See this thread about the humidity sensor in the rear view mirror assembly.

HVAC Control - for those over 50

30 years ago, most houses had a thermostat with two settings: How LOW the room temperature will go before the HEATER kicks on. How HIGH the room temperature will go before the A/C kicks on. Yes, you set a temperature range. There were two slider adjustments to limit "how warm" and "how cool"...

teslamotorsclub.com

If you want to try the deeper reboot, it's the "Power off" button in the service menu. See the manual for details.

 

[alexcue]

See this thread about the humidity sensor in the rear view mirror assembly.

HVAC Control - for those over 50

30 years ago, most houses had a thermostat with two settings: How LOW the room temperature will go before the HEATER kicks on. How HIGH the room temperature will go before the A/C kicks on. Yes, you set a temperature range. There were two slider adjustments to limit "how warm" and "how cool"...

teslamotorsclub.com

If you want to try the deeper reboot, it's the "Power off" button in the service menu. See the manual for details.

Personally done all that, and have done a "hard reboot" already too. I'm stopping short of unplugging the 12V and the disconnector under back seat. I'm already on last update so hoping the next Firmware update will fix it now. I can manually make it work in the morning so that the face vent works, but you lose the auto action. The evening seems to work okay for now, it's nice and cold anyway, in auto.

 

[Grognak]

I have the same exact issue. Just got my windshield replaced and it will only blow out of the upper vent while on auto. Nothing I have done seems to fix it. Anyone find a fix?