Yes there's supposed to be a little rubber elbow there. First 99 Burb had lost its elbow. The truck came off a ferd dealer used lot. They didn't know what it was,just that the floor would always be damp on the front passenger side. Stupid salesman "accidentally " spilled his coffee on the floor to cover it up. We found out about the elbow later from an air conditioning mechanic. Got one and put it on, fixed the problem. When next I get to the treasure yard, I'll see if I can get a couple of spares. That, ash trays for the doors, radio knobs, heater switch knobs, all that little stuff that's hard to find.....