My front defroster only blows on one side. Anybody have any idea how to fix it?

 

What year jeep? (im on my phone cant see all info) If its 97+ remove the radio bezel, remove a few screws slide the cluster bezel forward, then pop the upper dash panel off and make sure the plastic hvac tubes are slid into their correct places.

 

Found the Problem. Pulled of the radio bezel and removed the radio. There was about a 2 inch gap between the tube and the vent that the foam didnt cover. so i place some cardboard in there and it works great.. Thanks for the Help.