My '98 E320 A/C is no longer blowing cold air. Lately it has not been as cold as I would expect (though it is summer in Texas), but today it is not cold at all. Blower is working just fine.

I've never had a cooling problem before, so I don't know much about the refridgeration system. Is this a DIY project for this model? If I had a decent service manual I'd try and troubleshoot it, but I'm not sure where to start otherwise. Should I just take to a pro and pull out my wallet?

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1998 E320 120K mi
1991 Miata 80K mi
2001 Ranger 109K mi