Heater/Air Conditioner comes on by self

hi i have a 2005 santa fe 2.0 diesel auto and have same problem and cant find an answer as to why anywhere on the web. pls help

My 2010 Santa Fe is doing the same thing and it's really bugging me...please post if you learn of a remedy

Did anyone ever find out what is causing this issue? I have a 2010 as well and it is doing the same thing. They even just replaced the condenser for the A/C.

Mine is still doing the same, turning on by itself and not turning off...now I have the additional problem of the air conditioner turning off by itself when I want it on :(

easy fix ! my 2012 santa fe had same problem . I changed the cabin air filter and fix the problem since then . I think the dirty filter has something to do with it .

I just bought my used 2012 Santa Fe from a VW dealer and it has the same problem. Per the above post, I went to change the cabin filter but found that it was perfectly clean already, so that's not the cause of my a/c turning on automatically. If anyone else has any other suggestions, please let me know!

I was told it was the control panel causing the issue. Since I had already put in quite a bit of money on other problems, I decided to trade it in for a Toyota. Apparently the 2010 V6 model was known to have issues. Sigh

Was told it is a module Mine a is 2010 santa fe, told its common

I have a 2012 and it’s been turning on the a/c randomly for about 3 years now I’ve just been dealing with it never fixed it or looked it up how to fix it. I always change air filter- Now problem is when I turn on ac my car dies!!!! Great great!!

I have the same issue and after taking my 2008 Santa Fe in several times, turns out that you have to replace the AC & heater control unit. It’s an enclosed unit with just one plug at the back. There are so many complaints online about the same issue that I am certain that Hyundai knows of this inferior part but hasn’t done a recall because it isn’t a safety issue... it’s a dealer part and it’s expensive. My blower turns on and off or blows stronger or lower than it’s set to on it’s own. I cannot turn it off. Every time I press the off button, it just shuts off for about 10 seconds and turns on again... HYUNDAI, replace these defective parts!!!

I had the same problem in my 05 Santa Fe. It's the Ac-heater switch. The contacts heat up over use and time. This in turn either causes it to stop working or work when you don't even switch it from the off position. This is, like said above, a known problem with Hyundais. Thing is I've already replaced mine with an aftermarket one from Autozone (about 35$ or so) and it's happening again. Just something you have to deal with I guess.

Anyone get a definite answer on this??

It's exactly what I said. The AC/Heater switch that controls the fan.The contacts get heated up,become loose inside the unit and will make contact off and on. Eventually the blower won't work at all unless you mess with it and shimmy something under the edge of it. Basically you just have to replace it.

I repaired it shortly after I posted the question. Will likely happen again but it’s been 6 mos and it has been stable. I removed the heater/AC control panel and took it apart. Cleaned the contacts with isopropyl alcohol and a q-tip. It looked like the metal arm that makes contact with the board when you turn the control knob, rubs off the copper “film” on the board after a lot of use and also leaves behind a black residue which prevents the signal from making it to the blower motor. I added a thin coating of circuit board lubricant and put it back together. I actually cleaned any dust and debris that I could see from the transistors and components on the back of the circuit board as well for good measure. Works fine now but you do need to disconnect and reconnect the blower motor when your reinstall the control panel to reset it before it will start working again when you’re done.

Yes, this is a consistent problem. I’ve owned a 2003 and now own a 2011 and it happened with both. On the 2003 the radio would do it too. Hyundai should fix the problem for free. It’s obviously a defect that they won’t correct.

My Hyundai Santa Fe 2009 A/C come on and go off it self and come on it self after a long time. What will the course of it?

Have a 2012 Santa Fe with the ac/heat system problem. Been going on for 3 years. Went to dealer and I told the service rep about this and it seemed to be pretty common...all over the internet. He told me that I should not believe all that stuff on the internet. Needless to say, but this is my first and last Hyundai.

I got so upset with my heater coming on during the summertime I pulled on the the air condition max button started blowing cool air ever since got home sprayed it with some Electric cleaner haven't had any problems I guess over the times pushing the button was staying connected to the hot and cold have no idea but it worked

I got so upset with my heater coming on during the summertime I pulled on the the air condition max button started blowing cool air ever since got home sprayed it with some Electric cleaner haven't had any problems I guess over the times pushing the button was staying connected to the hot and cold have no idea but it worked.