heater problem help please

just got a 95 hyundai accent. There was a CD player in the dash I had a better one so I took it out. Put dash part back in but now the levers on my heater that you move to determine heat, vent, etc. no longer go side to side anymore. It's like they are stuck. So I'm wondering if it is just a cable problem and maybe the cable is stuck or something. Any info greatly appreciated