Celica Forums General Discussion General Windshield defogger and A/C

I noticed that when setting the vents to the windshield position, the A/C automatically turns on. Is there a way to disable this? I checked the installs section but couldn't find it.

Thanks

That's because in order to defog the front windshield, it needs to use the AC.

Why would you want to disable it, when you can just press the button to turn it off?

I haven't noticed that...

Yah, sometimes you just want to use heat to defrost not the A/C. Damn horsepowerless car, you can't pass with the defrost on!

I asked the dealer about that and they said there is no way of disabling it. It annoys me too. I want to just put it to run some air out the top and in the winter to defrost... why the hell would I want the AC on in the winter to blow hot air on the windshield???

you guys don't get it
the AC turn on for a reason
AC = compressed air = not humid = regulated temp
i forgot how the science works around all this but it's normal that the ac turns on
try this, when your windshield is humid (so humid that you can't see through it), turn the blower on without the AC..you will notice it takes forever or sometimes, it even makes it worst.
now turn the AC on and notice that the humidity on the glass disapears much faster?

all i know is that it has to do with a sensor in the car that regulates that.
trust me, you wouldn't want to disable that
it also serves same purpose when it's a a hot/humid/rainy day...

oh yeah, you guys just hit the button, don't be lazy!

My A/C doesn't turn on when I defrost the window.

it does, just the light doesn't come on.

In order to remove the moisture (the frost) you have to dehumidify the air, or Air Condition it.

I don't think you get it.

We are simply saying that we don't have the choice to "hit the button" and would like that option. It comes on whether you like it or not any time the car is set to windshield or windshield and feet.

I've owned cars before that didn't automatically put the AC on when it went to windshield and they defrosted snow and kept humidity off the window just fine.

^^ I don't think you get it.

Condensation is when a gas turns into a liquid. This is done by cooling the gas. Condensation is the opposite of evaporation.

Car windows fogging up on a cold day is an example of condensation. The water vapor in your breath is a gas, and as it comes from inside your warm body, it condenses into droplets of liquid on the cold inside surface of the car windows. If it's cold enough, that liquid will freeze on the window and become frost.

A car's air conditioner cools the hair down by removing the heat, and dehumidifies the air to remove moisture which causes condensation.

Without the A/C being on, it will take A LOT longer to dehumidify the air, and thus remove the condensation.

Lastly...

You can run the A/C and still have hot air come out of the vents, it will just be "conditioned air"

A/C doesn't mean cold, it means moisture free.

^^^^ never said it doesn't work well, and I know how and why AC works.
The original poster and others are just saying it would be nice to have the option not to use the AC every time it's set to windshield.

Why?

For more HP? Racing around with condensation on your windshield is idiotic.

Relax. You're right it works better.
Just sayin it would be nice to have control. What about cars without AC? They're all "racing around" blind?
That's idiotic.

They have to wait for the air to dry the condensation on the windshield.

I think Toyota would design something to work better, not worse.

Why would you want to turn the A/C off, and make it take longer? The whole thing is stupid.

Well in Canada during the winter I find that putting a car to defrost works very well and I don't find a difference from experience with several cars between "conditioned" air and regular hot air to defrost the window.

During summer, yes, it does work much quicker too clear fogging of windows. During the winter I would like the option to not use AC because fuel economy goes down enough due to cold weather driving that I would rather not use the AC every day during the winter.

Sorry if you disagree but that the way it is and that's the point of this thread. People would like the option to use the AC or not. I would still use the AC in many conditions but not all the time.

The A/C drops the fuel economy so little, you'd never see the drop noticeable (I got 32mpg in the summer full blast ac, 32mpg winter no ac)

ok.

I'd still rather not have it on ALL THE TIME.

then pull the panel off the front, and solder a switch onto the AC control board assembly to turn it off.

BTW, you might want to buy a couple of those boards, they break easier than Brittany Spear's hymen.

^^^lol!! nice comparison lol!

hahahha, nice! good idea.. but naaahhh. I'll leave it as is, I just don't use windshield unless I have to.

ps. Britney is weird now. She used to be my favourite.

If you don't want the AC to turn on when you hit defrost, then just crack your fucking window or sun roof and put it on outside air.

What's wrong with you people? You're getting your panties in a twist over this topic. I'm trying to fight with you.

I do "crack a fucking window" but we're aloud to say it'd be nice to have the option.