I have an '07 Elantra still under warranty (58,500)... sometimes, when i start the car, air will blow on and off even though the a/c switch is off... sometimes when i'm driving, air will start blowing on and off even though the a/c switch is off... the dealership said it couldn't "duplicate" the problem so it can't diagnose or fix it... any suggestions what the problem is? blower motor maybe? i'm sure it's under warranty, but how do i deal with the dealership when they tel me they can't "duplicate" the problem? warranty has about 1,500 miles left...

 

Automatic or manual controls?

Have you read your owners manual on how the system works?

Turning the A/C off doesn't turn the blower off. It just turns off the A/C compressor. The fan still blows with the A/C off. Do you mean you turn the mode switch to OFF. That turns the fan off but it does not prevent air from flowing through the system. As you drive, fresh air enters the system through the venys at the base of the windshield and will come out the vents.

 

manual controls... here's an example... the mode dial was on off... a/c button on the temperature dial was off... the fan dial was on number 4... i started the car and with the car in park, the fan started blowing air from the upper vents... then after a 2-3 seconds, air stopped blowing... couple seconds more, started blowing strongly again... then i started driving, air stopped blowing and didn't start again for a few minutes, then the a/c light on the temp dial illuminated and the air started blowing on its own from the lower vents... after a few seconds, it stopped... then it was blowing from the lower vents on off, on off... eventually it stayed on... again, all of this was happening while the mode dial was in the off position ... btw, i heard a clicking sound each time the air went on and off... thanks for your input...

 

Sounds like a similar problem I had with my Tucson:
https://www.hyundaiforum.com/forum/h...midently-7856/
https://www.hyundaiforum.com/forum/h...working-11687/

And like someone else with a 2007 Elantra had:
https://www.hyundaiforum.com/forum/h...cks-off-11501/

My advice, have the dealer replace the entire controls when it's still under warranty.