Having done a search and reading, my 1980 300d A/C works and cools, but the majority of the air comes through the defrost vents. I get a little chilled air out of the side vents by driver and passenger, the two center vents have little velocity and the air is not very cool. From my understanding the two center vents only provide fresh air, so this may not be an issue. The majority of air going to the windshield vents sounds like a vacuum issue. Is this vacuum pod behind the glove box? I also notice in order to get the blower to turn on, I have to to push in the defrost button and then switch to auto hi for A/C. Any thoughts?

You probably have some failed vacuum pods.

Hope this helps.

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2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

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