2009 Kia Rio, base model. 2006 Kia Sorento LX. 2010 Kia Soul +.
I have a 2006 Sorento LX that had the same issue. I drove it to work, blower was good. I went out at lunch and the blower wouldn't work. Checked the fuses, they were good. Drove it home with no blower in 90+ heat. Got it home and as an afterthought cranked it again after I had parked it. Blower started just fine and hasn't cut out since. I suspect a sticky relay in my case, but it also could be corrosion in the fusebox, which is what I suspect is going on with your vehicle. Try pulling the two fuses and hosing down the fuse sockets with electronics cleaner. CRC makes a great one they call QD. It's about 5 or 6 bucks at Walmart. If you know which relay it is, hose down the socket under it too. Good luck! Being without a working blower is no bueno.