Question regarding the Windsheld defrost

Posted this question in General JL but it didn't get far so I thought I'd post my query here.

It's pretty much winter up here in the Canadian Rockies and I had to use the windshield defrost for the first time this past week.



When I use the windshield defrost, I get warm air coming out of the green area but no airflow at all from the red area. (Of course this picture omits the passenger side of the dashboard but it's the same thing on that side.)

So the end result is that the center portion of the windshield becomes free of snow and ice but the edges remain frozen. What's up with that?

Is it just mine? Can someone hit the windshield defrost on their center dash (top left corner) and tell me if they get any airflow from the vents towards the ends?

 

My JL warms up quickly and is blowing hot air in no time. But it never alternates between hot and cold.

But as for my initial query, maybe it's a Jeep thing. I noticed someone even made a 3D printable diverter for his JK :
https://www.thingiverse.com/thing:184101

But the strange thing is that the JL seems to have the vents in place almost edge to edge. It's just that only the center vents seem to work.

 

Just to clarify, when in windshield or mixed mode, I don't feel any air coming out from the red area. The green area is fine. (The right side is not pictured but the same problem occurs on that side as well.)

The side window have a separate vent and they work fine.

Can anyone try this on their JL and let me know if this is the case on their Jeep?

 

Thanks, jebjkey! I really appreciate that.

I guess the red areas are just an accessory. Or maybe they're a feature which will be added in 2019.

Either way, I'm sure we'll be seeing more of these threads as the rest of North America starts to get snow.

 

The mixed position does the same thing. No air from the red area regardless of speed.

I'm thinking the red areas are not physically connected at all. Although I can't take a clear picture deep into the vent, there are changes to the structure at around that transition area.

The side window vents are separate. They consist of smaller vents on the ends of the dash and they work fine to defrost the side windows.