W124 blows hot air or cold

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Algoritmus

Active Member
Joined
Dec 6, 2010
Messages
88
Location
Reading, UK
Car
'94 W124 E220 Estate
Hi,

I have read every w124 hot air related threads.

I have a w124 w/o aircon with two temp wheel. If I set to the coldest position (till clicking) then it seems the douvalve close as the air change from hot to almost cold (not outside cold just warm...ish)

If then I set the wheel somewhere else the I get hot, without transition (like a switch: cold or hot).

My question is: How does it works? the wheel control the voltage for duovalve say from 5v to 12v or with different frequency close-open-close-open the valve?

I will do some measurements at the weekend , but I am not sure how it supposed to work.

Any idea welcome.

Cheers

A
 
Last edited:
Mine did something like this and it was a simple fix. The temp sensor for the cabin is in the roof lining and the air goes through the little "slats" in the interior light assembly. If you remove that assembly you may find that the air inlet is blocked up with old dust and fluff. Just blow it clean and see if that fixes it. Mine has been perfect since.
 
Thanks, I'll check it !!!
 

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