Front Defrost and A/C in 2019 1500

[Packerbkd]

It is around 5 degrees here. Is it normal that when I turn on the front defrost, that the A/C also turns on automatically? The defrost seems to work but I have to turn the A/C off every time. I tried searching he forums but not finding anything like my issue.

 

[rws1944]

Yes, my 2019 limited does the same thing. When I hit the front defrost the rear defrost and ac also turn on. Turning the ac off returns me to the auto mode.

 

[crash68]

Just about every manufacturer turns on the AC when the front defrost vents are enabled. This goes back to even cars built in the 80s. It helps defog the front window and the AC system will turn itself off automatically if it's too cold for it to run. You can leave the AC enabled, it won't hurt anything.

 

[Jim M]

My 2020 Limited does the same thing I believe the intent is to remove the moisture from the air. I'm amazed at how quickly it clears the windshield.

 

[Quint]

Correct - you want the A/C on when it is defrosting. If anyone is unconvinced, do a test by running defrost with and without a/c. Both will work but it will work better with the compressor running.

 

[KeithP]

You will also notice you cannot recirculate when in defrost mode. This has been a thing on vehicles for decades. Exception would be vehicles without factory A/C.