Fabia III hyperactive Aircon

[GlennC]

The aircon on our 1.2 litre Fabia III has decided it will run all the time. No warning light, just refrigerated air out of the system whenever the engine is running. Up until this month it has worked properly - that is, it's been there when we wanted it, and not there when we didn't, under control of the dashboard button with yellow tell-tale light. Now it's always on regardless of any control settings and the interior of the car gets impressively cold, which won't be a joke when October comes.

 

I'd like to know where to look, what to hit, and what's likely to be the cause. Who can help?

 

(I read the posting "Air condition always on" but it didn't seem as though that discussion was going anywhere, so I've started afresh.)

[J.R.]

Climatronic or manual?

[AGFalco]

If you set the temperature control knob to hot/red do you get hot air?

 

Thanks, AG Falco

[GlennC]

Manual: and if I set the knob to hot/red, you can feel the warm air battling it out with the refrigerated air.

[SuperbTWM]

Possibly a stuck N280, you really need VCDS to see exactly what is going on here.

Edited 27 August, 2020 by SuperbTWM

[GlennC]

Thanks for the suggestion, but I might need some help with the acronyms... I looked up the "N280" so now I know it's a control valve, but is it somewhere I can access?  And if it's stuck in the "on" position so I have permanent A/C, can I give it a manual poke so that it's turned off permanently instead?  And I have no idea what a VCDS is except that I don't own one!

 

(Learning on the job here...)

[J.R.]

That would be my thought also, it could however be permanently commanded due to another failure (temp setting knob?) so I would start by disconnecting it and if no different then give the area around it the good news with a hammer & drift, not the valve itself as the external part is plastic.

 

It is located at the rear of the compressor at about the 14.00 position viewed from the crankshaft pulley, you can just squeeze your hands down to release the connector.

[GlennC]

Thanks J.R., that gives me a starting point at least. (Next time it stops raining).

[FabiaGonzales]

Do note the AC does still run when the heat is on, it dehumidifies the cabin and stops it steaming up inside. I've always left the AC on.

 

Unless you mean that pressing the button it won't turn off and always kicks out freezing cold air?

[GlennC]

The car won't be going anywhere for a few days, so I can't take my investigation any further just yet. I'll return to the topic as soon as I have done another short drive - meanwhile thanks for the suggestions everyone, very much appreciated.  I can fix my 1949 Riley even if it goes direly wrong: but uncovering the hidden secrets of a 21st century Skoda is different!

 

[GlennC]

Well I located the "N280" and gave its electrical connector a good workover, and I'm pleased to say I think it's now sorted.  Thanks to all involved for the pointers, and for not calling me a muppet.