alfdoc -

There is nothing left to take off to get a better view, but I think I know what is happening here.

This morning, I used a very long flat blade screwdriver to give the white piece a nudge in the right direction. As soon as it moved a little bit (without much force required), the flap was free to move back and forth by hand. I left it in the fresh air position, started the car, pressed the recirc switch and watched the flap move to the recirc position. Toggling the recirc switch to the off position left the flap locked in the recirc position.

Next, I used the screwdriver to nudge the arm coming out of the actuator back out. Once again the flap was free.

As I was moving the flap back and forth, I could see enough of the linkage operation to understand (or at least I think I understand) how it is designed to work.

The black piece below the white piece (which turns out to function as an idler) is a sector which has an arm that connects to the arm coming from the actuator as well as some gear teeth which drive the white idler which, in turn, moves the flap's lever arm.

It appears that the flap locks in the recirc position by a slight over-center action when the actuator arm is fully withdrawn. Under normal conditions, when the recirc switch is set to off and the vacuum removed from the actuator, the return spring would supply enough force to move things in the right direction and return the flap to the fresh air position.

In this case, the spring (which we see in the two photos) is connected to the black sector, but it's other end is free, so there is no restoring force at all. (The fact that the spring is not extended in the photo should have given me a clue!)

I can't really see where the free end of the spring is intended to go. I do see what appears to be a broken nub on the side of the HVAC housing, but it might just be the remnant of a molding sprue.

My plan is to get a cheap long screwdriver, file a notch near one end of the flat blade and then use it to extend the spring and see if there is something it will snag onto.

If that doesn't work, I think I'll just place the flap in the fresh air position, disconnect the vacuum valve so I don't inadvertently send it to the recirc position, put everything back together and live with it for a while to see if it's worth removing the HVAC system to either replace the housing or cobble a new mounting for the free end of the return spring.

Once again, thanks for hanging in there with me on this.

- Bill