I did a search and didn't find anything about this, unless I wasn't using the correct keywords. Just recently I noticed that my 2009 Santa Fe activates the A/C when I choose the defroster/floor button. And when I mean that the A/C is activated, I mean the green light on the A/C button turns on. I'm not talking about the A/C compressor itself, although I'm sure that's turning on as well. I have to press the A/C button to turn it off, and then just the defrost button will be lit. This happens whether you have the blower selector on floor or bi-level or the upper vents...it doesn't matter. I just don't understand why all of a sudden it is doing this. I have so many complaints about this SUV after owning it only a little more than a year that I wished I had chosen a different vehicle..

 

Nevermind...I fixed it. Disconnected the negative battery cable for a few minutes and reconnected it and now everything is back to normal. Had to reset my radio and time stuff, but that was expected.

 

The owners manual for my Accent says the a/c compressor will run if any defroster position is used, reguardless if the a/c light is on. Every car I owned that had a/c did this, to help defog the windows. If the outside temp is below freezing, the compressor should not run. If you really don't want the compressor to run with the defroster on, you could pull the fuse that goes to the compressor clutch.

 

^^^ While that is true for most cars, it's not for the 2009 Santa Fe. I looked it up in the owners manual and it clearly says it can be turned off.

 

I have a 2016 Elantra GT and this just started happening to me within the last 2 or 4 days.
No idea wtf is going on. Never had an issue.
New battery was put in back in November and haven't had any issues.

Gonna try the neg terminal and see if it helps me too.
🤞🏻
Thanks

 

What does your owner's manual say regarding this ?