Yeah, I'm hoping this fixes the problem too. If not, I'll try something else. You asked about the part? Here's how I ordered it:
1. Click on FastLane at the top of this page.
2. Click Online Catalog on the left of the page.
3. Click your year.
4. Click Mercedes-Benz.
5. Click your model.
6. Click Climate Control.
7. Click ACC Mono Valve.
8. Buy it. For my year and model, the part number is R3022-32577 and the price is $92.09. It arrived in a few days. I've purchased several things this way and never had any problems.

Let me know if you have any questions.

Techie9