My Dad and I did the Ac in my 300SDL:
-both drier switches
-Freeze 12 freon/similar to FR-12.
I'll tell you. This baby blows good and cold. Just like R-12. Way better than R-134a.
I'm glad we put the Freeze-12 in. Only cost be $8.00 with tax for a basic can. Well worth the money for the cold here in Florida.
99 C230K Sport