13 replies to this topic

[Antithesis]

Hello, I hope someone can help.

I've read several topics on this subject but I have the opposite problem to those I've read. My heater distribution works everywhere except on de-mist. There appears to be no difference between footwell/screen and screen only (these are next to each other on the control knob). Air blasts out of the footwell on both settings, There is a very slight breeze to the screen when fan is on no. 4.

I've taken the control panel off, checked that there is a vacuum, poked a straightened paper clip in the pipes to see if any gunk in there, seems clear.

Mine is the basic heater with no air-con. Any ideas what to try next please?

Many thanks.

[Hearsepilot]

Check the vacuam motors are opening and closing the flaps.

[Antithesis]

Check the vacuam motors are opening and closing the flaps.

Sorry for not replying sooner. Any suggestions on how to check the flaps as they are inaccessible as far as I can see. There is no sound change when selecting between the screen/footwell modes on the control and air comes out the footwell in all three positions. When selecting between facia/footwell you can hear the flaps opening/closing.

Thanks for any help.

[Antithesis]

Still got this problem, not good this time of year. Could it be the switch or is that wishful thinking? Don't know what else to try. There is vacuum if you put your finger over the pipe behind the controls, not a great deal but I'm not sure how powerful the suck should be.

Anyway, any other suggestions very welcome.

[Antithesis]

On the slim chance someone will be reading this;

I located the problem to the silver canister to the right of the glovebox that moves the yellow lever to direct flow. When you select windscreen, the pin that comes out of the top of the canister starts to rise but not very much. I pulled it up and down with my hand a few times but it was very stiff. I pulled it to the extreme and got air flowing to the windscreen again. Selecting footwell moved the lever right down but going back to screen only moved it a little. I sprayed WD-40 around the area as a desperate attempt to free it but it didn't work.

I assume this is unfixable without removing the dash which isn't going to happen. Please let me know if I'm wrong (if there's anyone there).

[Hearsepilot]

Do you know any gynocologists? Seriously have a go, they are held on with just a couple of bolts iirc.

[Antithesis]

Hello Steve, thanks for the reply. What do you mean, have a go at removing the silver thing?

Also, I checked the vacuum from the pipes near the clutch pedal. The one coming from the engine is quite strong and you can hear it sucking when you remove the pipe from the box. The one going to the dash is fairly weak in comparison, is that right? Not sure what happens in that box between in and out.

My vents always take a couple of seconds to open/close when you move the distribution knob, is that normal? I'm wondering if there isn't enough suction.

[Hearsepilot]

I would hold off on stripping anything more out until you've checked the vac lines for blockages and kinks, my vents switch instantly so something isn't right with yours.

[Antithesis]

...my vents switch instantly so something isn't right with yours.

Thanks Steve. Yours is vacuum as well then, not motors? As I mentioned there is much less vacuum coming from the 'box' under the dash than going into it. Maybe there's something blocking it in there. Not sure what the box does, will have to see if it is able to be removed without stripping the dash.

[malmeida14]

Mondeo 1.8TD 1995 Ghia with air con, just have the same problem: no air to the windscren. Any solution?