Step One: remove negative battery cable (safety and engine computer reset)
Step two: replace strip fuse in little plastic casket, that is solely for fan function.
Step three: pull Klima relay and check for corrosion on contacts, clean, replace.
-if there is corrosion, that's definitely the problem, if not, it could still be, but the compressor, speed sensor, and freon levels need to be checked to specs



If you still get no response from HVAC blower, search forum for "Brian Carlton Blower circuit" and begin diagnostics.

Blower operation has nothing to do with compressor operation from a failure perspective. Mercedes makes these cars to fail safely. Blower is needed in winter for defrost, which is why your vacuum modules for the windscreen vents fail in the open position.

Unless there is a wiring harness or push button unit failure, these two problems are most likely unrelated.

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77' 300D, "Cartman" SOLD @ 150K (didn't know what I had)
83' 300SD, "The Superdon" 325k+ @ 28mpg
95 E320 wagon, "Millennium Falcon" 231k+ @ 24 Mpg
95 E300D, "Sherley" 308k @ 33.69 Mpg, currently anticipating a head
99 Suzuki Intruder "Trudy" @ 45 mpg