Air conditioner blower

I actually was having the same issues with my Tiburon 2.0L I4. Mine appears to be physically damaged. The previous owner re-wired the radio to the fuse box and pulled the fuse to the rear wiper. In the process of that, it appears that he pried the wrong parts from the entire control unit and broke one of the clasp parts that hold it together. What may be happening is you may have corrosion on the contacts if you live in a really humid place, western NY is brutal on cars here. The part inside itself is actually a circular disc with little contact nubs. I found that when I started encountering problems with it, you were actually able to push in the knob. In that case, fidgeting with the knob by pushing it in might re-align the disc inside and make some settings work better. (temporarily, of course) Dealer and OEM replacements are EXPENSIVE as it usually means replacing the entire bezel. I have a base model so I don't have any of the extra switches and such. Try E-Bay for a "heater control bezel" or something like that. You may have to revise the search querry. Good luck. Finding one of these used is a chore.