Engine Disable automatic AC when in defrost mode

Disable automatic AC when in defrost mode

How do I do this? I hate that my corolla turns on the AC automatically. The search option sucks in this forum. It came up with nothing. Thanks,

Josh

What how can your ac automatically turn when all you do is turn it defrost... Are you sure that the ac automatically turns on by itself???....

My 98 Prizm does the same thing. The ac comes on automatically when you select full defrost, but it statys off if you select floor/defrost.
It is a little irritating.

defrost setting on most late model cars are hooked up to your a/c. some early american models are like this also. i think japanese models didn't come out with these until late 90's. the cold air helps clear up the window faster.
some car, the a/c light will actually come on when u change to defrost - some don't. you can tell if it's on or not coz your rpm will drop when the a/c compressor kicks in.

annoying thing is that when u leave your setting at defrost, you'd be driving your car with a/c on all the time in the middle of winter and your gas usage will shoot up way high!

yeah, I know. It sucks. Is there a way to disable it besides cutting the belt to the compressor?

If I rember right it is there to keep the system moveing .like oil your o-ring and compresser.If it sits for a long time it could leak or you will have problems with the compresser.I would just leave it be.It is doing its job.

Actually the AC compressor comming on will not produce cold air, if you put your hand up there with the defront on you will feel heat. All its doing is help remove the moisture from the air so that the air you blow at the window will absorb the moisture from the window and thaw it out much faster. Just thought I would throw that out there

yeah..the ac turns on when you change to defrost mode. i hate it when i ac start runnign while i wait at red light.

I just recently purchased a used HVAC unit (the heater controls in the dash) on ebay. When i looked at the back of it to figure out how everything works, I noticed there is a button behind the vent selector that gets pressed when the switch is on defrost or floor/defrost. With a little coaxing, you can turn the gear in there a little bit so it doesn't get pressed on defrost. That way you have to actually press the AC button to turn the AC on. Once i fugured this out I decided not to use it, but it can be done. If you look at the back you should be able to figure it out. I know I only use defrost when absolutely necessary cause it sucks gas hard. But if you turn the selector to floor only, and turn up the fan a notch or too, you'll notice it still comes out the vent under the windsheild, just not as hard. But once the window is clear, its enough to keep it clear.