The speed is monitored by a 'LM2903 chip - Low Power Low Offset Voltage Dual Comparator'. I do not have schematic for any Klima, gasser or diesel. I was wondering any electronic whizkid has done any simple change to monitor the compressor rpm. This is to make sure the serpentine belt is not chewed if the compressor is stuck. Let me open up a few Klima and reverse engineer a fix, hopefully.

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Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.