A random question...
I knew that when you put your defrost on in your car the a/c comes on even if you are applying heat to your windshields. I just started noticing that now when I put my defrost on in my car that the aircondition light is not on. My question is does your a/c turn on in your car when you put the defrost on or does it stay off?

 

On all of thecars that I've owned over the past 19 years, the compressor engaged whenI turned on the defroster although the a/c light didn't come on. That may not be true for all vehicles. If I remember tomorrow, I'll[sm=icon_rtfm.gif].

 

i noticed that the other day. when i had the ac on in the day and then used the defrost at night the ac came on. but when i only had the vents on with ac off and used the defrost it didnt turn on so i guess it depends on what u were doing before.

 

Sorry about these run on posts...

Well my buddies pontiac and my girlfriends mistibishi both have their a/c light on with the compressor on as well when you turn the defrost on.
I don't even hear or feel the compressor on when I turn thedefrost on although I may need to double check. Once I push my a/c button in it will blow colder air than outside if I choose to put it on cold with the defrost on.

 

No.Mine does not. But I do know that the manufacturers like the AC to come on every once in a while especially in the winter so the seals don`t become dry, stick then self destruct. May be it does come on(without the lite)just enought to lubricate the seals. Might be a good question to ask your dealer.

 

on most modern cars the AC will come on when you use the defrost setting, which directs air to the windshield, or the windshield/floor, I think. The reason the AC comes on is that it creates dry air and if you want to clear your windows of moisture it will do it faster than just using hot air like they did 30-40 years ago (with Ford it could be much more recent!).
I had used the setting one night and for the next couple of days I was wondering why my engine would make a whining noise at shutdown! Forgot the AC was still on!

 

It's very common for people to use their defroster and not realize that their compressor is running. I'm surprised the car manufacturer's don't illuminate the A/C light or have a seperate telltail when the compressor is on during defrost mode.

 

The A/C will come on with the defrost turn on. You need to remove the moisture from there are for it to work effectivley. Otherwise it will be like all the old cars that would take days to clear up.

 

You should be able to see the compresser running when you open the hood with the defrost on.

 

And do NOT use the braille method... [sm=icon_stickpoke.gif]