The other day the blower fan on my 87 300D stopped working and the Central Locking System which I long considered dead came back to life, all during the same car trip..suddenly the CLS started working normally.....and I know this may not be too analytical, but I am wondering if the two are related through a Grounding Problem

Check the overvoltage protection relay behind the battery (it is behind the plastic splash shield underneath the windshield), it is probably corroded, and it is likely at fault.

thanks, that was a very good clue

My ignition switch has a very small amount of play in it. If the key isn't just to the left of the run position, the blower won't run, but everything else seems to work OK.

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1987 300D Turbo
2000 VW Golf TDI
2008 E320 Bluetec

Vacuum for the power locks is provided by an electric pump. And yes, with electricity any wacky behavior is possible.

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Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
Chain Elongation References

that was a good clue.