Originally Posted by Jeremy5848

The diagram probably came from the W123 climate control manual, which I no longer own. Clicking on the link brings you a small copy of the diagram but my PC gives me a (+) magnifying glass symbol for the cursor; clicking that enlarges the diagram and it is very legible in the large size. I still have my copy of the file that I uploaded; it is 4446 X 4415 pixels and 1.88 MB in size so there should be no problems seeing all of the detail.

Jeremy