How to test recirculate or outside air vent function

[Revenelson]

On our 93 325is:

I just finished installing a new blower motor, and as I was enjoying putting the puzzle pieces back together, I thought I would make sure the outside air vents next to the blower fan close and open correctly. From research, I think the only time the outside air vents close is when the recirculate button is pressed. Also from research, I think the movement is controlled by an electric motor.

I started the car, pressed the recirculate button, and nothing. The vents are staying open.

Am I testing the vents correctly? Is there an electric motor that moves the vent doors?

Steve

[Eric93se]

How is the air pressure in the car, are the vents pushing air well? I have a broken door on the left side of the blower motor (completely gone), I have a new part coming in the mail (got a good price). My pressure is very poor, another member had the same problem and putting a new door fixed the issue. I would imagine if both doors are open on yours you would also have poor pressure.

Not many member take that area apart and study the mechanism, so I doubt there will be much feedback. I should get my part in a few more days and hopefully install it on a warmish day, so hopfully I'll be able to give you some feedback on the operation.

[Revenelson]

Well, yes the air pressure is good, I think it should be good either way with the doors opened or closed.

My thinking is that it should do the same thing most of my cars do when the inside air or circulate button is pressed, and that is to sound different. Louder usually. Now the fan and box is covered so I can't see what is going on in there.