Yeah… no… that’s only the newer generation of vehicles, the enshittified ones that assume everything for you.
Back in the 90’s and 2000’s, the engineers had common sense and if the temperature dial was set anywhere above 50%, the air conditioner would never turn on, as it’s a waste of energy at that point.
Uhhh my 96 civic had an air conditioner button, and it also turned on when you turned the defroster on.
You’re making shit up, it’s a simple interconnection, and the physics of air conditioning removing moisture has been known for a long time.
During winter snow constantly gets inside of a vehicle, so without an interconnected ac with defrost, the interior would always fog up. It just may not light up the button, but defrost turns the ac on.
Does absolutely nobody understand the difference between FOG vs FROST?
The deFROSTer is meant to gently melt snow and ice FROST off your windshield using the heater. Kinda fucking counterintuitive to blow freezing air at a frozen windshield, the FROST will never thaw that way.
The deFOGger is meant to dry the humidity off your windshield on a hot humid day, that uses the air conditioner on hot humid days.
Two different systems, for two different climates. deFOGger vs deFROSTer are two completely different modes of the climate controls.
My 78 Chrysler was designed to use the AC in defrost mode even in a winter blizzard and was much more effective and drying the windshield because of it. Most heating/cooling system in cars were combined much earlier than that to take advantage of dehumidifying the air. It also has the benefit to run the compressor to keep lubrication and stop seals from drying out in the AC system that would otherwise not be used to months at a time.
There are some vehicles with separate heating and AC systems, (mainly cheap or aftermarket units) but the vast majority run together. (At least in North American cars.)
I said 90’s through 2000’s, I said nothing about 2010’s or beyond.
I do not have much of any experience in working on anything past 2005.
Anything past 2014 is what I call new generation enshittified, as that’s around the year they basically started tracking everyone, refusing to offer printed service manuals (Hayne’s/Chilton), stop offering parts and requiring ‘owners’ to take the vehicle back to the dealership for repair.
I’m all about the right to repair. Your 2015 is a new generation enshittified thing, sorry.
So why are you discounting what people who do use modern cars are saying as incorrect if you don’t know much about it? I’d wager most people probably aren’t driving 25-35 year old vehicles anyway so at best you’re just stating outdated and irrelevant knowledge.
Knowledge is never irrelevant if you’re still driving around a 30+ year vehicle. Knowledge is relevant across all years, here’s reference from 1960-2025 year range vehicles. I’m not fucking retarded…
What I do know, first hand experience, is if the air conditioner goes out before the heater core heats up, well you got about 15 seconds to roll the windows down for airflow to keep the windshield from fogging up.
My 04 turns on the AC with the defrost, so did the 01 I used to drive, both base-level economy boxes so actually wait what the hell have you been driving?
Yeah… no… that’s only the newer generation of vehicles, the enshittified ones that assume everything for you.
Back in the 90’s and 2000’s, the engineers had common sense and if the temperature dial was set anywhere above 50%, the air conditioner would never turn on, as it’s a waste of energy at that point.
Uhhh my 96 civic had an air conditioner button, and it also turned on when you turned the defroster on.
You’re making shit up, it’s a simple interconnection, and the physics of air conditioning removing moisture has been known for a long time.
During winter snow constantly gets inside of a vehicle, so without an interconnected ac with defrost, the interior would always fog up. It just may not light up the button, but defrost turns the ac on.
Does absolutely nobody understand the difference between FOG vs FROST?
The deFROSTer is meant to gently melt snow and ice FROST off your windshield using the heater. Kinda fucking counterintuitive to blow freezing air at a frozen windshield, the FROST will never thaw that way.
The deFOGger is meant to dry the humidity off your windshield on a hot humid day, that uses the air conditioner on hot humid days.
Two different systems, for two different climates. deFOGger vs deFROSTer are two completely different modes of the climate controls.
My 78 Chrysler was designed to use the AC in defrost mode even in a winter blizzard and was much more effective and drying the windshield because of it. Most heating/cooling system in cars were combined much earlier than that to take advantage of dehumidifying the air. It also has the benefit to run the compressor to keep lubrication and stop seals from drying out in the AC system that would otherwise not be used to months at a time.
There are some vehicles with separate heating and AC systems, (mainly cheap or aftermarket units) but the vast majority run together. (At least in North American cars.)
deFROST != deFOG
I’m starting to gather that most people don’t have any clue how to properly use their environmental controls.
My 2015 vehicle does it that way (a/c on for both), so it’s not exactly a recent change in design philosophy…
I said 90’s through 2000’s, I said nothing about 2010’s or beyond.
I do not have much of any experience in working on anything past 2005.
Anything past 2014 is what I call new generation enshittified, as that’s around the year they basically started tracking everyone, refusing to offer printed service manuals (Hayne’s/Chilton), stop offering parts and requiring ‘owners’ to take the vehicle back to the dealership for repair.
I’m all about the right to repair. Your 2015 is a new generation enshittified thing, sorry.
So why are you discounting what people who do use modern cars are saying as incorrect if you don’t know much about it? I’d wager most people probably aren’t driving 25-35 year old vehicles anyway so at best you’re just stating outdated and irrelevant knowledge.
Knowledge is never irrelevant if you’re still driving around a 30+ year vehicle. Knowledge is relevant across all years, here’s reference from 1960-2025 year range vehicles. I’m not fucking retarded…
https://lemon-manuals.la/
What I do know, first hand experience, is if the air conditioner goes out before the heater core heats up, well you got about 15 seconds to roll the windows down for airflow to keep the windshield from fogging up.
My 04 turns on the AC with the defrost, so did the 01 I used to drive, both base-level economy boxes so actually wait what the hell have you been driving?
Do people understand the difference between FROST vs FOG?
FROST != FOG
In my old '90s car, heat only just made the fog worse. You had to have AC on too. Though it did trust you to know that and turn it on yourself.
And this is the proper way.