MK7 "Random / "Stupid" Questions Thread"

[imthanick_a]

It’s done this on every car I’ve owned for a while. Weird thing is if you leave it on defrost when the car is off for a while it behaves differently, but On cold mornings I usually crank the heat, turn to defrost and hit the AC button to kill it. There’s no humidity when it’s 4 degrees out...


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The humidity is introduced into the car by you through breathing. Notice how when more people are in the car, the windows fog up. More people, more breathing, more humidity. AC (usually) automatically selects recirculation mode to help scrub the humidity introduced into the car through your breath

Edit, I was wrong about the re-circulation thing. You can't turn it on when in pure defrost mode. I usually use face vents and defrost combo mode which is why I thought this

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[adam1991]

Anyone know why my AC automatically turns on nearly every time I turn on the fan. It keeps turning on whenever I try to defrost my car in the morning or just run the heat on a cold day. Turns on as soon as I turn the fan, even if the heat dial is over Hi. Recently I haven't intentionally run the AC at all because its 45F outside so I'm not sure why it loves being on so much.

Air conditioning has much less to do with "make cold air" than it does "remove moisture from the air".

You asked for defrost; to do that, it must present DRY air to the windshield. And that's what the AC system does--it dries the air. Removes moisture.

Just go with the flow. Really. The engine heat is MORE than adequate to overcome any cooling of the air that the system does. You can have hot air, as hot as you want, *with* the AC on to dry the air.

And what you really want inside the car is the ability to remove the moisture that your body exudes, before it just sticks to the windows and removes visibility.

 

[Strange Mud]

Anyone know why my AC automatically turns on nearly every time I turn on the fan. It keeps turning on whenever I try to defrost my car in the morning or just run the heat on a cold day. Turns on as soon as I turn the fan, even if the heat dial is over Hi. Recently I haven't intentionally run the AC at all because its 45F outside so I'm not sure why it loves being on so much.

+1 to what was already mentioned. AC comes on automatically when the flow is to the windshield. I don't like it either but it's normal

 

[heiney9]

The A/C coming on with the defroster on has been a VW thing since atleast the MK5, maybe even earlier. Can't remember if my MK3 did or not.

 

[Shane_Anigans]

The humidity is introduced into the car by you through breathing. Notice how when more people are in the car, the windows fog up. More people, more breathing, more humidity. AC (usually) automatically selects recirculation mode to help scrub the humidity introduced into the car through your breath

Mine tend to fog up the most when there are only 2 people in the car, while it's parked...

 

[-Dutch-]

Mine tend to fog up the most when there are only 2 people in the car, while it's parked...

Relevant username...

 

[vj123]

Mine tend to fog up the most when there are only 2 people in the car, while it's parked...

Pretty common in A^2 city! [emoji850]

 

[imthanick_a]

The A/C coming on with the defroster on has been a universal vehicle feature since the 90's, maybe even earlier. Can't remember if my MK3 did or not.

Fixed it

 

[doak]

In case it hasn't already been mentioned:
For most effective defogging activate the recirculate button to better remove moisture from cabin air.

 

[adam1991]

No.

 

[Wrath And Tears]

In case it hasn't already been mentioned:
For most effective defogging activate the recirculate button to better remove moisture from cabin air.

So I don't know about the rest of you, but when the CC is on defrost, you can't activate recirc. I've pressed the button a bunch of times and it never comes on. Same with my 98 A4 which turns the AC on when you hit defrost. Seems like a function to me.

 

[-Dutch-]

Science, Bitches!

http://www.roadandtrack.com/car-cul...astest-way-to-defog-windshield-nasa-engineer/

 

[Finglonga]

In case it hasn't already been mentioned:
For most effective defogging activate the recirculate button to better remove moisture from cabin air.

The opposite, you are trapping damp air in the car.

 

[Jarbear]

I've heard folks use the term "surfer key" idk if it has the chip in it but no transmitter. You pop off the cover of the real key hole (drivers door look in manual).

you will also have to manually turn the ignition rather than push a button... too much work for me.

Mud's got Kessey...I gotta learn how to deal with that.

When the fob dies, you use the key to open the door. Then since its kessey, you hold the dead fob next to the cover where the key normally goes, and press the start button. It'll start right up. At least that's what I've read

 

[Shane_Anigans]

The opposite, you are trapping damp air in the car.

Unless it's really humid outside, in which case, the system won't have to work as hard to remove moisture from the air. However, that's not a common scenario.