The climate system is making and odd noise. clickclickclickclickclick.... very fast repeated clicking.

It does this when heat is selected on the temp roller, and the button (marked EC) next to the off button is pushed in. It also does it when the next button to the left is pushed in. When the next button (with 2 solid arrows) to the left is in, it doesn't make the noise.

After messing about with it, I suspect the gizmo that operates the flap that directs the air through the dash vents and the floor vents may be having a problem. The sound seems to come from inside the knee pad area, just to the right of the center console.

With the ACC off, I rolled the dial to full-on A/C let chill air come out for a while, then pushed the button marked EC. I then rolled the dial to full heat. The clicking didn't happen, warm air came out the dash vents. But when I turned the engine off, then re-started it, the clicking began immediately.

Any ideas? Maybe photos of the potential problem?

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1st MBz: 1982 300SD
2nd MBz: 1987 300SDL
3rd MBz: 1995 S420
4th MBz: 1987 190DT
5th MBz: 1984 300SD w/1983 300DT engine
6th MBz: 1999 C230k I'm 3rd owner, got it w/57,235 miles.
and manages Mom's 2007 R320 CDI