Help! My '97 C230 has no AC and it is hot in the south!

The reason for no AC is that the compressor is not running, however the root cause is unknown. I CANNOT turn the compressor by hand but there doesn't seem to be evidence of a problem other than that (i.e. leaks of any sort that I can detect by the naked eye). I tried putting voltage directly to the clutch, but I never heard anything click.

Any ideas on how to troubleshoot?

Thanks!

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dyazdani
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'97 C230
'03 Honda CBR600RR
'92 Ford Explorer