so what happens when a vehicle has both. recir and max on a/c panel. So max is just recooling again and recir is taking the air from inside the cab instead of outside.

Does the max on out trucks do recir from inside or recool the already cool air???

 

I'm not sure exactly what you're asking, but here goes: The recirculate button is optional for all AC options that are NOT max ac. Max ac automatically puts recirculate on and it cant be turned off if the dial is on max ac. (At least I think that's how my 06 works, definitely could be wrong)

 

And that should indicate that the out vents at back of cabin are working, not stuck shut or blocked.
Still, being noisier in not Max AC seems to be opposite of anything I've read or experienced in the past. That is you hear the blower as louder because you have opened a door from the cabin directly to the blower wheel and in close proximity to it. If using outside air, that door would be shut and the outside cowl vent would be the closer as far as nothing between blower wheel and your ear. I guess the heater core and/or evaporator along with vent tubing otherwise help baffle the sound from blower wheel.
Yet, in my case it seems to be noisier if not in Max AC and sounds like air flow is being restricted somewhere inside case.
And that is what makes no sense to me since the only difference between the two positions should be whether it is getting outside air or cabin air.
Help?

 

The only vehicle I've seen that seems to have both is my wife's KIA. That is there is a dial for the functions, defrost,etc. and it has a Max AC position. Also three buttons, turn compressor on or off, rear defog, and recirculate. Max AC automatically kicks in recirculate and pushing recirculate button will do nothing. Any other selected position will change recirculate via button except defrost selection. It is almost as if Max AC selection does the same thing as choosing recirculate button on, but not vice versa. Fortunately there is a little light on the recirculate button to let you know if it is on or off. Fan speed is totally separate from other functions.

 

Yes KIA has that on their cars. The point was what do the buttons actually do???
I am not sure what the OP was asking about. Usually when you put max a/c on there is a difference in the sound and feel of how the air comes out of the vents..

The bigger question to me is what does the max a/c thing do exactly. Does it actually recir or does it just run the cooled air back over the coils to cool it more. The KIA reference was to add to the confusion of what does the max a/c do. Assuming the max a/c does the recir on our trucks, What does the max a/c and the recir, that are as stated separate on the KIA do?

I myself just assumed the max a/c on our trucks did recir. Is there a diagram somewhere that shows how the air flows thru the ducts.

E NET rider you may have to pull it apart to find out if the motor that moves the door is going out,, that may cause your problem.

 

The AC always runs the air through the cooling process no matter what, recirculate just means it's cycling the air inside the truck through the system instead of air from the outside.

All max AC is is regular AC plus recirculate and blowing out of all vents. It's just a convenient way to achieve these settings.

 

All systems I am familiar with have one door for outside or recirculated air. No other door changes take place with that decision unless you change temp and that controls blend door or doors on dual systems. Because the fan makes some noise and proximity to the inside inlet it is usually noisier when drawing inside air instead of outside. Also you can hear an increase in sound level at the outside cowl when switched into one of the not recirculating functions.
To achieve max cooling you need to be recirculating the inside air and every ford system similar to this one does just that when in the Max AC.
That is what seems to be working although maybe not cooling as well as it should be. This could be something with freon loop or blend function or possibly some other unknown gremlin. Before tackling freon loop I want to address the issue I do see related to the case or ducting so that I preclude having to work freon loop twice.
And that red flag arises from an increase in air noise within the case/ducting and decreased air flow from dash vents. Unless ford did another stupid, there is something wrong and am looking for help to troubleshoot instead of just tearing apart.

A "stupid", not just ford's. Those idiot AC designers put appearance ahead of function when it comes to dash vents.

 

MAX A/C uses only the dash outlet vents, same as for NORMAL A/C and the VENT settings.

 

I caught that slight miss of wording as well and thanks for noting to the benefit of any reader. BTW the airflow also seems restricted in vent selection which only turns compressor off by function. And is perceptibly noisier airflow in the case in any selection other than Max AC, excepting the OFF position.

 

Moving into cooler weather and last nights high humidity, slight rain, forced me to attempt clearing windshield. That function sucks if working as Ford designed, or as I've previously questioned, there is some issue with air flow in any position other than Max AC. Guess I'm being forced to check inlet and attempt learning how the air is supposed to flow through case.
What I was sensing is that in defrost the air flow is inadequate.

 

You need to explain because the alldata diagrams reflect differently. That is they are supposed to be from the ford manuals and the only difference would be outside or inside air. So where is the cause of less volume?