W124 Heater controls

[ecossebev]

Now that the warmer weather has arrived, I decided to get some cool air into my '91 230TE. However, I must have disconnected/broken something whilst changing my head unit, because now the temperature stays constant on both sides. Makes no difference whether the temp. is turned up hot or cold, constantly blows out hot air (leaving myself open with that one). Any pointers as to what I should be looking for before I remove the control panel will be much appreciated.
TIA
Sean

 

[Druk]

Check the douvalve. Defaults to open iirc.

 

[MBK]

Check the douvalve. Defaults to open iirc.

yes your right the duo valve defaults to open if there is now current going to it. best way to test this if you dont have a multimeter is to have someone sit inside the car whilst you put your hand on the duo valve, then get them to switch from hot to cold you should feel a click on the duo valve if theres no click the duo valve is either stuck or there is no power going to it.

 

[ecossebev]

Where will I find the duo valve?

 

[ecossebev]

Sorry.....found the thread.