it depends what car u have but on most fords there is a button tht says
A/C When tht button is on ...the A/C Will Work With The Fan ...When the fan is on the A/C is Also On So Make Sure The Switch Is Off When You Turn Ure Fan On .....Good Luck Tha ac turns on when in defrost because the ac dries the air out, and drier air cleans the windows faster.
Turn the AC or the Defroster off.
Many auto manufacturers engage the AC compressor when the defroster is used because the AC system also dries the air. In a humid environment the drying effect of the AC can help keep the windshield clear.
Turn the defroster on. If you have a separate AC switch, turn it on also. The AC should come on with the defroster automatically, but might not. If no AC, set the vent control to outside air instead of recirculate.
If you have the defroster on, the ac comes on automatically.
comp may cycle when you have the defroster on
Most of the time it means that the AC refrigerant has leaked out or that the AC doesn't work for some reason. Understand that most vehicles engage the AC when the defroster is on because the AC will dry the air, clearing the windshield quicker. If you turn on the Defroster and the AC light flashes, it just means that the AC won't turn on.
Turn off the defroster.
Some vehicles automatically turn on the a/c when you turn on the defroster. A/C removes humidity from the air and allows the defroster to clear the windows faster.
or any other car, mostly the AC removes moisture On my 2008 Corolla, the AC light does not light up when the defroster is turned on. However, it DOES appear that the AC compressor is used. (my 2008 is the same as 2003 thru 2007, it is not the redesigned Corolla which an 09 in the USA.)
yes on thoes cars and most cars the ac kicks on to circulate the heat for the defroster
Yes, the windshield defroster will turn the A/C compressor on.
Check to see if you've turned the defroster on. The AC runs in that mode to dehumidify air inside the car. Cheers