2015 Lacrosse fan speed issue?

[Caleb17]

I have a 2015 Buick Lacrosse Leather and have noticed the fans being weaker than usual lately. I don’t know what’s wrong but I’ve done some testing and trial and error and this is what I’ve learned:

- When I press auto, the dash vent and floor vent lights on the controls turn off, and if I turn the fan speed up they seem to blow strongly.
- When I turn the dash and floor vents back on, they become weak again, despite being at the same fan speed.

Any ideas???

 

[DrivenDaily]

When all the air comes out of just the vents, there will be more pressure and therefore more speed.

When you add the floor vents, some of that air has to be shared and so the pressure and speed at any one location will be less than before.

Normal.

 

[HotZ28]

Do you have an owners manual that explains how the system works??

 

[Caleb17]

When all the air comes out of just the vents, there will be more pressure and therefore more speed.

When you add the floor vents, some of that air has to be shared and so the pressure and speed at any one location will be less than before.

Normal.

I understand that, when the fan is on Auto, it’s stronger than even dash vents alone, though.

 

[Smith1000]

You could try changing the system filter, which is behind the glove box. I also found the air flow, in my '13, to be weak. I had to keep the speed set fairly high to get air flow and it was somewhat loud. I found that a new air filter also restricts the air flow quite a bit. I completely removed the filter, as a test, and it blasted air through the vents. Instead of the specified replacement filter, I just use a filter material that is used for a home ac unit. It does not filter as well as the specified replacement filter, but the air flow is much better and the speed does not need to be set as high as before.

 

[Caleb17]

You could try changing the system filter, which is behind the glove box. I also found the air flow, in my '13, to be weak. I had to keep the speed set fairly high to get air flow and it was somewhat loud. I found that a new air filter also restricts the air flow quite a bit. I completely removed the filter, as a test, and it blasted air through the vents. Instead of the specified replacement filter, I just use a filter material that is used for a home ac unit. It does not filter as well as the specified replacement filter, but the air flow is much better and the speed does not need to be set as high as before.

Interesting, I’ll have to consider that. If that is the issue, though, it wouldn’t seem to explain how Auto can still be more powerful? BUT, I may have been wrong about Auto being stronger than dash only. So maybe it is normal and I just never noticed (but I feel I usually have good attention to detail about things like that). We recently got my wife a newer Enclave that we’ve been using more, so maybe I’m just comparing mine to that, too.