Thre is a cable that attaches to the vents...seems like alot of people break them or dont hook it back up after puttin a radio in.
Look up under the console on the drivers side kind of bekind the cig lighter.There is a clip that holds the cable and the lever to attach to.You can flip it with your hand to open or close it..
The trick is to hook up the csble on the vent first ,then feed it down as you put the center together,then hook up the cable under the dash last.