To help dehumidify the air
comp may cycle when you have the defroster on
The ac unit compressor will run when it is in defroster mode and heat setting is on.
Generally, yes. It depends on the outside air temperature.
Turn off the defroster.
Yes, the windshield defroster will turn the A/C compressor on.
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.
If you have the defroster on the ac will run. It dries the air to help clear the inside of a foggy windshield quickly.
Bad compressor
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.)
The fans will probably stay on while the defroster is on because the A/C compressor is running.
no, the truck was made to balance the air temp going threw the vech
AC compressors will cycle like that when there is insufficient refrigerant.