Assuming your heater, air conditioner, and blower motor all work correctly, you should use your heater defroster in cold weather, and your air conditioner defogger in warm weather.
Note the difference in environmental control terms…
DEFROSTER > Used for cold climate, heater, to melt the frost off your windshield.
DEFOGGER > Used for warm humid climate, air conditioner, to dehumidify the air.
Failing either heater or air conditioner, welp, just do what we do and roll the windows down.
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.
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.
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?
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.
Humid and warm: use heat
Cold and dry: turn on a/c
I think you got the right idea, just backwards…
Assuming your heater, air conditioner, and blower motor all work correctly, you should use your heater defroster in cold weather, and your air conditioner defogger in warm weather.
Note the difference in environmental control terms…
Failing either heater or air conditioner, welp, just do what we do and roll the windows down.
Both of those settings turn on the A/C to remove moisture.
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.
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.)
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.
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?
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.
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.