First do yourself a favor and start it with AC on HI, if blower does not come on reach up and give the fan squirrel cage a couple of good 1/2" nudges clockwise and see if it fires up. If so, the blower motor brushes are shot and it stopped on a dead spot. The motor is sealed but it may be possible to open it up and replace them.

Here is the W140 regulator retrofit. Does not fix a dead motor. http://forums.mbworld.org/forums/e-class-w210-sponsored-bekkers-imports/153918-early-w210-blower-motor-regulator-replacement-diy-here.html

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)