Condensation on outer windshield in Max AC mode

[chibuick]

Hi all, I’ve been running the air conditioning on Max AC I’ve noticed condensation building up on the outside windshield. It looks like some of the cold air is directed through the windshield vents and not fully through the mid vents causing that part of the windshield to get cold and build condensation on the outside.

Is this normal on these LeSabres or do I have an actuator that is failing or mis-calibrated? I think I read on the forums that by default the actuator for the vents default to the windshield and so I’m just not sure what I should do. Pic attached. Thanks!

 

[DrivenDaily]

This is normal on just about every car with AC.

Re-route the air to come out of the vents and floor and it'll either diminish a lot or totally disappear.

Imagine a glass of iced tea on a humid day. With it sitting on the counter, it'll collect water on the outside of the glass. It's condensing moisture from the air due to the large temperature delta. You're doing similar by blowing really cold air on the glass, and the hotter, more humid air outside allows it to condense moisture from the air.

If you still want it on the WS, run the wiper now and then.

 

[chibuick]

Hi, thanks for the quick reply, but maybe I wasn’t clear. I was under the impression that the Max AC setting only routes air through the mid vents and not through the windshield at all. The windshield defrost is a separate mode. I don’t want any air coming out of the windshield vents, just the mid vents blowing directly at me. So what I’m saying is it’s blowing air through both the mid vents and the windshield when I thought it should only blow through the mid vents in the Max AC setting. I don’t have the air on the windshield setting.

Hi all, I’ve been running the air conditioning on Max AC I’ve noticed condensation building up on the outside windshield. It looks like some of the cold air is directed through the windshield vents and not fully through the mid vents causing that part of the windshield to get cold and build condensation on the outside.

Is this normal on these LeSabres or do I have an actuator that is failing or mis-calibrated? I think I read on the forums that by default the actuator for the vents default to the windshield and so I’m just not sure what I should do. Pic attached. Thanks!

 

[HotZ28]

Hi, thanks for the quick reply, but maybe I wasn’t clear. I was under the impression that the Max AC setting only routes air through the mid vents and not through the windshield at all. The windshield defrost is a separate mode. I don’t want any air coming out of the windshield vents, just the mid vents blowing directly at me. So what I’m saying is it’s blowing air through both the mid vents and the windshield when I thought it should only blow through the mid vents in the Max AC setting. I don’t have the air on the windshield setting.

Defrost is the windshield flow setting. If the vehicle is cooler inside than outside in high humidity air, you will get what you described. When this happens, you may have to add a little heat to the defrost air to clear the outside in addition to using the wipers. Being a LeSabre custom, I assume you have manual sliders for controls?

 

[chibuick]

Yes, thanks, it is manual controls, but I don’t want the air coming from the windshield at all. If no air comes from the windshield then there would be no condensation. How do I stop the air from coming out of the windshield in the Max AC setting without having to adjust the temperature?

Defrost is the windshield flow setting. If the vehicle is cooler inside than outside in high humidity air, you will get what you described. When this happens, you may have to add a little heat to the defrost air to clear the outside in addition to using the wipers. Being a LeSabre custom, I assume you have manual sliders for controls?

 

[DrivenDaily]

Even with a brand new system that functions perfectly, some air will still eek out of the floor and WS vents, although it should be minimal.

In every car I've ever driven, the setting for Max AC causes the air to come out of the dash vents and turns on Recirc. If yours has too much WS air, then try putting the AC in Vent mode and selecting Recirc manually. If it still has air on the WS, maybe your car that's 20+ years old has some leakage in the HVAC box.

 

[chibuick]

Even with a brand new system that functions perfectly, some air will still eek out of the floor and WS vents, although it should be minimal.

In every car I've ever driven, the setting for Max AC causes the air to come out of the dash vents and turns on Recirc. If yours has too much WS air, then try putting the AC in Vent mode and selecting Recirc manually. If it still has air on the WS, maybe your car that's 20+ years old has some leakage in the HVAC box.

Thanks, I’ll try the “normal” setting with recirc turned on and see if it makes a difference!

 

[jotzgr]

If the vehicle is cooler inside than outside in high humidity air, you will get what you described.

Agreed. Entirely normal operation, especially in hot, humid weather. I get it a lot at night when I am running AC. Have to swipe the windshield to clear it every few minutes. Nothing wrong with your system if air is coming out of the dash vents like it should. Not just on my Lesabres either, pretty much any other vehicle does the same thing under similar conditions with AC running.

 

[imidazol97]

The HVAC has a small amount of bleed air that goes to the floor or to the defrost openings, like people
have said. That cools the windshield and if outside humity and temperature are right then condensation occurs.

On my 93 leSabre the bleed to the defrost when in floor mode or bilevel was so great that it dried my
eyes due to the "breeze" from the air coming out of the defroster. Dealer checked the heater vane by disassembling it,
I was told, but it was normal. Just the air coming around the internal vanes.

 

[BuickGirlFromMars]

The HVAC has a small amount of bleed air that goes to the floor or to the defrost openings, like people
have said. That cools the windshield and if outside humity and temperature are right then condensation occurs.

On my 93 leSabre the bleed to the defrost when in floor mode or bilevel was so great that it dried my
eyes due to the "breeze" from the air coming out of the defroster. Dealer checked the heater vane by disassembling it,
I was told, but it was normal. Just the air coming around the internal vanes.

the 93 lesabre and park avenue had a procedure to adjust that because of how uncomfortable those situations were
I believe it went away when they put a few electric actuators to work under that dash(but not all of them till 2000)

 

[silverbullet04]

100 percent normal, especially on humid early mornings and nights.