Check my page for pics. . .
of the Mercedes VFC. It requires about 5 lbs of pressure to keep the pin fully "pressed" in; this causes the fan to freewheel.
The bimetallic strip (bms) is made from steel and brass. So it's amazingly stiff! There's pics of some tests of the Sachs VFC in menu #19 and #20.
Not sure of the mixture but it appears to be alot of steel. Also takes very high heat (above 110C) to ge sufficient "bend" to fully release the pin. That's why they don't work very well!
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Regards . . . . JimF
'94 S500 Cpe
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