Vents always on

Has anyone else come across this?

No matter what position selected on the control unit, always get a moderate flow of air from the vents. When only the vents are selected, air still blows mainly to the floor.

I thought it was the control unit, so I replaced it to no avail (btw, GM now has just the airflow control switch available for under $50 so you don't need to buy the whole panel). I traced the problem back to the air box behind the dash. The vacuum actuator that connects to the door that controls the vent was disconnected, and the little pin it fits onto was broken off.

GM says it's a bear to do, minimum of 5 hours labor and the whole box has to be replaced (the part is only about $30). Anybody else run across this? is it really that bad a job to do? any other possible fixes?

Thanks.

I thought the constant air is actually a "safety feature" that they started putting on cars back in the '90s. There will always be fresh air entering the car to prevent a dangerous build-up of noxious gasses. I can't imagine this would prevent harm, but I think the vent door is always open.

I've heard that if you select the recirc button and turn the fan to off, the vent door will close since it thinks the blower is going to be providing recirculated air. Plus since the fan is off, there will be no air movement. I don't know if this works, because the constant venting does not bother me.

On a related note...Which "Control Switch" are you talking about? Is this the A/C switch, or maybe the Fresh/Recirc switches, that cause the A/C to turn off without warning?

I've heard that if you select the recirc button and turn the fan to off, the vent door will close since it thinks the blower is going to be providing recirculated air.
That's what I do. I notice a small amount of air flowing through the vents, but it usually doesn't bother me. If it's cold, I'll press the Recirc button and the flow stops.

Maybe I should have been more specific. I have found the problem, the spot where the vacuum actuator connects to the vent door is broken. My question is if anyone else has come across this problem, and if they fixed it themselves if they have any advice for the job. It looks to be a major pain in the A## (have to remove the entire dash and center stack), but by doing it myself I'd save $400+ in labor to replace a $30 part.

Thanks in advance.

The control switch I was referring to is the one on the right, to select where the air is blowing from (vent/floor/defroster/etc.) If this switch goes bad you can replace just the switch now, you don't have to buy the whole panel anymore.