My 1978 300D blows hard but puts no hot air in the cabin. I thought it would be the simple fix of rebuilding the monovalve. But I went to A&F imports today and was told I don;t have monovalve in this car. Instead there's a solenoid and to fix it I have to replace it with an $800 part!

Any suggestions or answers for me. Thanks.

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1987 300TD; 166,000 mi/267151 Km - had to make room for the dog
1973 220D; mileage ??????
1978 300D; 178,000

i believe they are referring to servo-you can do a search for evil servo lots of info.if it is the servo there are ways to manually bypass it so at least you get heat when you want it,but no ac.

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95 e320,87 sdl,79 300sd

If your 300 has AC then you'll have the evil climate control servo. Which also means you have a push button climate control panel.

If you don't have AC you likely have the manual climate control and have a grey valve on the firewall near the battery that may be broken, or disconnected. This also means you have the dials for climate control.

Pic 1 is has the climate control servo circled.
Pic 2 is the valve for the manual climate control

Attached Thumbnails

   

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