Rear Air Controls not working

I have a 2002 Yukon and the rear air controls stopped working. The front vents operate but there is no air for the rear. I checked fuses and took the rear console apart and seen no loose wires. Any suggestions?:confused:

take it in and get the rear actuator looked at...probs with em 02 thru 04

Thanks Damien. I was hoping it was something that i could clean or replace but I guess I will take it in.