On the GM's it does.... on ours, all it does is recirculate the air inside the truck.

 

Then why does it seem like the fan is blowing more air? lol

 

This makes sense. Since my panel doesn't allow me to put the system into max, not only does the fresh air vent door stay open, but the fan speed isn't pushed into the max speed range...which may also explain why I feel like the volume of air isn't sufficient.

For the last few months, we've been at or over 100 degrees with no relief or rain to cool things off. Basically I have been using regular A/C, not max A/C, which any normal person would use during heat like this.

This is important for two reasons, first, the A/C is trying to cool the outside air instead of cabin air which would continually get cooler while on max and the fan speeds are not up where they would be on max.

I found the correct panel on Ebay, placed the order, and will hopefully have it by next week. I'll install and test, making sure to watch the fresh air vent and fan speed changes based on max or regular A/C.

 

On my Durango, switching to max does indeed increase fan speed. I will test this on the truck when the new panel arrives.

 

Hope you get it sorted out.
I live in Texas, so 8 months out of the year I have the control set to Max A/C. lol

 

There is no difference in current flow between High Heat, or High A/C. On max A/C, the blower is drawing air from inside the cab, hence, less inlet restriction for the fan. So, it blows harder.

 

Touche! I'll buy that explanation.

 

+1.........

 

Makes perfect sense. I've been driving the truck a lot lately trying to fix all the little things that went out over the years it was owned by my Wife's Grandfather.

Anywhere under 90 degrees and the A/C feels good and cold and I'm happy with the abilities and air speed from the vents. However, above 90, and I can barely feel cold air at my face. The air from the vents is good and cold but by the time it gets to my face it's already warmed up.

I'm anticipating a big change when I get the new switch panel. Not only will the air speed increase but I think cooling cabin air instead of outside air will allow it to better keep up in the 90+ range of summer heat.