I have an 84 300d that the buttons do near to nothing. Once in a while I hear some kind of a vacuum sound (tsss- sound of air releasing) happen but If I press the buttons I get the blower to come on and sometimes I can get a breeze coming out of the vents when EC is on but never a strong breeze out of the defrost.

The other prob is this... when I'm going 75 on the interstate I can't get that car to heat up for nothing. If I'm going under 50 it'll get hot on EC but still no defrost. But if my speed is over 50 forget heat. That car's an ice cube.

Any clues...

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-E300d '99 350k
-Suburban '93 220k
-TDI Jetta '03 350k
Sold
-F250 '96 7.3
-Dodge Ram 12V
-E320 '95 200k
-E320 Wagon 1994 155k
-300d Turbo '87 187k miles
-E320 1994 200k
-300d Turbo '84 245k (sold to Dan62)
-300d Turbo '84 180k
-300sd '80 300k
-7.3 Powerstroke Diesel 15P Van 500k+ miles
-190d '89 Non Turbo 2.5 5cyl 240k (my first MB)
Tom's Imports of Columbia MO Ruined the IP in changing leaky delivery valve O-Rings - Refused to stand behind his work. Mid-MO MB drivers-AVOID Tom's.