No air to windscreen - W124!

[ajs37]

Hi all – I have a 1991 300E 24v (124.031) – I bought it a year ago to replace my ageing 190e – and I love it – but I do have a small problem:
I cannot get any air onto the windscreen at all!

Hot air from the side vents is fine, cold air from the centre vent is fine, hot air from the passenger and driver wells is fine - but nothing from the vents below the windscreen.

The controls are 2 thumbwheels for Temp, a fan speed control (working fine), a direction control (which seems a bit stiff in certain positions – but seems to direct flow ok, apart from the windscreen), 3 switches – A/C on, Re-circulate and demist.
There is a problem with the Climate Control (A/C compressor has gone off to have new seals fitted), but this shouldn’t affect airflow onto the windscreen (local, respected, Air Con specialist confirms this)

I have searched this forum and other places – I also have a 2 CD service manual (which does work with the use of Steve Nervig’s programme), and I can find some references to ‘monovalve’ / take out the whole dashboard / remove the blower fan etc., but none of these references gives a clear process for diagnosing and repairing the problem

Has anyone had this problem, or knowledge of this problem – and how did you solve it? I am prepared to spend time and a reasonable amount of money sorting it out, as having to open windows occasionally does take the shine off a good drive!

Many thanks

Andy

 

[tamrsoft]

The Air Control on most models operates a pair of rotating stalks into the heater unit, these can be accessed by removing the facia panel in the centre console. If it has been removed before and then replaced without lining up both stalks onto their corresponding shafts on the heater box, you can get this effect. On mine, one stalk was connected and the other left hanging free (shoddy re-assembly by someone), this resulted in normal airflow to all vents except to the footwell.

 

[ajs37]

The Air Control on most models operates a pair of rotating stalks into the heater unit, these can be accessed by removing the facia panel in the centre console. If it has been removed before and then replaced without lining up both stalks onto their corresponding shafts on the heater box, you can get this effect. On mine, one stalk was connected and the other left hanging free (shoddy re-assembly by someone), this resulted in normal airflow to all vents except to the footwell.

thanks! - now that does sound like a possible solution (as I know that the fascia has been taken off before)! I can see how you re-attach the stalks at the control end - but how do you get at the heater box end? (please don't say 'remove the dashboard'! aarrgghh!!)
Cheers
Andy

 

[tamrsoft]

The heater controls are on a small removable panel just behind the facia and can usually be pulled away as an assembly exposing the front of the heater unit with its protruding shafts. It's fiddly but you just have to line up the stalks from the heater controls onto the heater unit shafts as you press the control assembly back into place. You do not have to remove the heater unit or touch it. The shafts usually have a spigot on them so that the control stalks can only be fitted in a fixed orientation.

 

[ajs37]

thanks - I'll have a go this weekend!
Cheers
Andy

 

[ajs37]

just an update - problem is now fixed! only took half an hour as well
Thanks!
Andy