On a roadtrip last week the passenger dash vent above the cupholder stopped blowing air. All of the other vents still work including the window defroster on top of that vent. I thought it was an actuator but I can't imagine there is an actuator for the one specific vent. I pulled the vent out just to make sure the little flap wasn't stuck closed but that isn't the case and there was no air blowing without the vent unit installed.