2007 Santa Fe A/C Turns on By Itself!

[MarilynM]

I was riding today with the windows opened and I felt cold air coming out of the car's vents. I looked down and the A/C was turned on; I shut it. A minute later it turned back on by itself. This happened over and over again until I got home and turned off the engine. Of course, it's now 5 years old, with 58,000 miles on it, so out of warranty. Strangest thing I've ever seen.

[pare_john]

Was the front defrost on by any chance


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[MarilynM]

No, the defrost wasn't on.

[canderson]

Do you have the standard A/C system or the super delooox (digital display ala the Limited) model? You didn't post the model of your '07, so we're only guessing.

[keith86d]

we too have the same issue with our a/c in our 2007 santa fe. have noticed that it turns on when ever we turn on our defrost setting or if we switch to the defrost setting from a vent setting. would this be a fuse only problem or a larger overall electical issue? any ideas would be helpful. we own a canadian model GLS with the 3.3 v6.

[canderson]

@keith86d
I believe this is how your vehicle has been operating since the beginning. In order to avoid having the defrost operation create front window fogging at lower temperatures (the normal ambient humidity being circulated onto the cold windshield), the A/C is turned on in an attempt to dry the air to avoid this.

[keith86d]

no it really only started this year during the cooler weather just after the car came off of warranty

[MarilynM]

I have the GLS 2.7L V6 4-speed automatic. The defrost was not on. It was a cool day and I had the windows open. I drove to the store. Went shopping. On the way home, the A/C turned on all by itself. I hit the "off" button in the middle of the A/C dial. A minute later, it turned back on again. It happened over and over. When I came home, I told my son who drives the 2007 Elantra I bought for him. He told me the same thing happened to him in his car also, but it just stopped on its own. It's the craziest thing I've seen in any car I've ever owned. I bought this car in April, 2007 and nothing has ever happened in the five years I've owned it. Now that the bumper-to-bumper warranty is expired, this happens.

[MarilynM]

My 5 year, 60K mile warranty expired in April of this year.

[canderson]

Originally Posted by keith86d

no it really only started this year during the cooler weather just after the car came off of warranty

Then it has just recently started working properly! Not sure about which page it's on in your 2007 manual, but on page 141 of mine, it's pretty explicit (emphasis mine)...

When the "Defrost" button is pressed, the
" " [icon for fresh/outside air] mode will be
automatically selected and the air will be
discharged through the windshield defroster
nozzle, side defroster nozzle and side
ventilator. To assist in defrosting, the air
conditioning will operate according to the
ambient temperature.

What would be wrong, however, is if you subsequently set the outlet position to avoid defrost (e.g., feet only), and the A/C remains on.