This may come off as a stupid question, but I don't care.

When it rains (not sure about snow yet), my windows get unbearably foggy. Even if I take the defroster and leave it going (after it's warmed up) for the entirety of my drive, it doesn't seem to do anything but make my testes all sweaty. Sticks on the rear window, side windows, windshield not so bad.

So one, I understand it's happens when cold air mixes with warm air, yeah? Well, I do have a crack spanning across my windshield from like the bottom left, diagonally up to about a foot right of my rear view mirror. I know, awful.
Would my doors or windows possibly not be sealing very well? Or is so much cold air getting through the crack in the windshield (if that's possible).

And even so, how come the defroster doesn't seem to help with it at all. And yes, I'm aware that the word defroster applies to frost, but...

 

A seals broken in your window I'm pretty sure that's the problem, but how to fix it is another question.

 

Turn on the air conditioner, if you have it. Later models do that automatically when the air selector is on defog. Also set the temperature **** to full hot and let them fight it out. The air conditioner removes mosture from the air before it is heated and sent to the windshield. This only works when the outside temperature is higher than 40 degrees F.

Also if you have a leak in the car causing a lot of dampness in the seats or the carpet, it will move to the windows.

 

Turn on the AC and the heat/defroster at the same time, heating the car and taking out the moisture? Never heard that before, how does that work, and why does it only work at 40+?

For the seals, on the outside of at least one window, the top where there's that plasticy-rubbery seal where the window goes up into, is that the seal? I've noticed on at least one window, that rubbery part at the top outside folds underneath, is that it?

 

well your cars never sealed.... air will always get into it... otherwise youd die.LOL

first thing i recomend is CLEAN YOUR WINDOWS!!!!! inside and outside and thats it.....

i tried that antifog crap last year and the side of the windshield that i just cleaned was alot less foggy than the side i used that antifog on. so i will never use that crap again!!!!!

 

It's hard to explain why turning on the A/C works, but it does, so just try it. American cars and later model Civics all work that way. Also put the air control on recirculate so you are re-using the dried air inside the car instead of the 100% humid air that is out in the rain.

Below 40 F, the pressure and/or temperature controls won't let the compressor engage. So pushing the A/C button does nothing. But it won't hurt anything though.

 

I'll try to give this a shot. When the A/C chills humid air, water in the air is removed by condensation. Heating the air with the heater further reduces the air's relative humidity. Hence, the net effect of running the A/C and heater simultaneously is a massive drop in the relative humidity in the cabin, thereby allowing for the most efficient drying out of fogged windows.

 

unless your car doesnt have working ac or any at all.LOL

my 96dx ac isnt even fully installed yet.... ive been putting it off for awhile now. i have the parts mostly besides a new drier unit.
i gotta get the ac fixed in my 99 first so when i sell it it wont have any problems....

 

Alright, yeah
I just cleaned my car probably a week or two ago, did the windows with the power-washer on the outside and one time with Invisible Glass, then the inside twice-over with Invisible Glass.
And good explanation, it makes sense enough.
And as Addicted said, are there any good anti-fogs? Rain-x? Which one did you use, so I know not to use it.

And any way to keep that outer seal from folding under itself when I put the windows up?

 

well i used rainX antifog.

but what you mean by outter seal folding under itself? j/w

if your talken about the top of the window track.... im not positive..... maybe your rubber seals are dry or dirty or just catching and fliping under. mine tries to roll alittle in a few places but i just crank the window alittle harder and usualy it flips out and seals alright.
tho i believe i need to replace my window regulator since it doesnt want to roll up straight and even and has some slack. at least im hoping the regulator is the problem with mine.