Disable automatic A/C activation? (2024)

Driving to work this morning, I discovered the truck was turning the A/C on, on it's own. What I wanted was pure external air vent, no heat, no AC. I found this absolutely infuriating to the point that if I knew it did this ahead of time this would be serious points against buying this truck. I hope I'm completely overlooking something here.

Here's a photo of how I had the climate controls set:

To me, this says system on, fan running, no heat, no defrosters, no AC - should equal external vent, right?

A bit of background on the morning - We had just had an absolute downpour, but the sun was peaking out and the temp was climbing. It was very humid and muggy. But, it wasn't all that hot so it wasn't uncomfortable. This is speculation on my part but I'm pretty sure, the system was detecting high humidity and going "Ope! Just gonna turn the AC on there for ya!"

Ice cold air would start blasting out of the vents for maybe 30-60 seconds, then it would turn off again and go back to normal venting, bringing in pleasant air. At no time did any of the AC lights turn on, and attempting to toggle the AC or entire system on and off, did nothing.

Really hoping there is a way to completely override this as I absolutely cannot stand a HVAC system thwarting my instructions.

Welcome to the world of technology where the manufacturer is always "smarter" than you. Yes, you have all the A/C turned off, and you want only fresh, vented, ambient temperature air from the outside, but alas, Ford says, "No, what you really meant is that you wanted dehumidified air so as not to fog up your windows, so we'll go head and turn on that A/C compressor for you." Enter Ford's patented "Enhanced Windshield Anti-Fogging System (EWAFS).

https://fordauthority.com/2022/03/ford-patent-filed-for-enhanced-anti-fogging-window-system/

https://static.nhtsa.gov/odi/tsbs/2021/MC-10200995-0001.pdf

These vehicles (along with my wife's Explorer ST, which is where I first experienced a vehicle trying to outsmart me) have a humidity sensor, and when it reaches a certain threshold, the BCM turns on the compressor, effectively turning on the A/C, and freezing your butt off as you drive merrily along simply trying to enjoy the aroma of a spring rain. Not only this, but it overrides your recirculation and vent direction settings as well.

As far as I can tell, you have a few options:

• Turn the temperature up. The compressor will still kick on when the sensor tells it that the air is too humid and may fog up your windows, but at least you won't turn into a human popsicle in the process.
• Turn the system off. When it happens, you can just turn the whole HVAC system off. Not ideal, but it does stop the compressor from engaging.
• Forscan. There is a setting that turns off the EWAFS. I turned it off in my wife's Explorer. I'm not sure it's fully functioning, because I swear it came on again the other day, but it may have just been cooler outside than I thought.
• Sell the truck. Like you, I simply REFUSE to own a vehicle that overrides the settings I choose for any part of its operation that allows me to make that choice.

I'm not familiar with fords system, but I know that most HVAC system with dehumidification (should) not turn on the compressor if the temperature target is colder than the actual temperature.

I have no idea if this is accurate in your case and it's possible it might turn on the heater if you do that. Something else you could try. There might be a sweet spot where neither heating or cooling would turn on. Again I don't know the logic for is using, but it might be worth a try to set the target temp a few degrees warmer and see what happens.

PawnX said:

I'm not familiar with fords system, but I know that most HVAC system with dehumidification (should) not turn on the compressor if the temperature target is colder than the actual temperature.

I have no idea if this is accurate in your case and it's possible it might turn on the heater if you do that. Something else you could try. There might be a sweet spot where neither heating or cooling would turn on. Again I don't know the logic for is using, but it might be worth a try to set the target temp a few degrees warmer and see what happens.

Click to expand...

My 2015 Escape always seemed to turn on the compressor when my temp setting was cooler than ambient temp. This was even when the A/C was not enabled. Not sure if they used a humidistat for that, though. Maybe it has to do with the auto-mode, but the indicator light on the A/C button is only on if I press it.

MAV said:

As far as I can tell, you have a few options:

• Turn the temperature up. The compressor will still kick on when the sensor tells it that the air is too humid and may fog up your windows, but at least you won't turn into a human popsicle in the process.
• Turn the system off. When it happens, you can just turn the whole HVAC system off. Not ideal, but it does stop the compressor from engaging.
• Forscan. There is a setting that turns off the EWAFS. I turned it off in my wife's Explorer. I'm not sure it's fully functioning, because I swear it came on again the other day, but it may have just been cooler outside than I thought.
• Sell the truck. Like you, I simply REFUSE to own a vehicle that overrides the settings I choose for any part of its operation that allows me to make that choice.

Click to expand...

Sometimes I just love the internet. Thanks much, this is very helpful. I haven't started dabbling with Forscan yet but I'm adding this to the list to look into when I get there.