I have a 2005 Nissan Altima. All if a sudden today while driving the a/c started blowing as if it were set to high (it was set on low). I tried turning it off but it still stayed on high. Anyone ever encounter an issue like this? The a/c won't turn off until I completely turn off the car.
Is it just the ac or does it run on high even on heat? If the blower motor is running on high no matter what the setting, the you might have a bad relay.
You're probably right. I have also experienced my stereo volume goes up on its own from time to time as well.
Most likely your blower motor relay then. The part is pretty cheap. The labor may not be depending on where it's located on your car.
Sounds like your a/c resistor. A bad relay wouldn't cause it to be stuck on high, but it'll be the easiest to check so I'd start their just to make sure.