2005 Octavia ii TDI 2.0

 

I have a strange intermittent problem with the blower on my climatronic system.  I haven't been able to work out anything other than sometimes it works and sometimes it doesn't.  It will just start or stop randomly when I'm driving along.  When it's working, there are no strange sounds or other signs of wear and it doesn't make a difference if it's set at high or low temperatures. 

 

The only clue I can find is that when it isn't working, the recycling button doesn't work (the light doesn't come on), but when it is working it does.  

 

The recycling button always works when I switch on the ignition, but the light goes out shortly after (maybe 10 seconds).

 

I'm guessing something is loose somewhere and vibration is causing a contact to make or break.  I've checked all the fuses in the engine bay and by the dashboard and they are all seated properly.  Is there anything else I can check without taking the whole car apart?

Chaps, sorry to revive an old topic but I'm getting the same issue with my Octavia II TDI 1.9. I have just replaced the blower motor as this seems to be most recommended around here, but the issue is still there. Symptoms are exactly as described by @lkdjsdk, the blower will work then randomly stop for a second or few (or sometimes for a few minutes), then it will randomly come back to life and will work for a few seconds or minutes before it goes again.

 

Any ideas on where to go next?

Does it only happen when you are cooling and in a humid atmosphere?

 

What you describe could be a defrost cycle of the evaporator.

It's been doing it for a good few months now, so it's been through cold/winter and hot/summer weather, and I've not been able to identify any signs/patterns of what could be causing it. It also starts happening from starting the car (i.e., when engine is cold), but it continues even after a long drive. It happens even if I have the air con on "ECON" (i.e., switched off).

 

Initially when it started was very intermittent and it would work for a few hours without a hitch before stopping for some time but in the last couple of months it's turned into a more frequent issue (i.e., it would stop a lot more frequently) - and because that's the case, the aircon also doesn't kick in or switches off automatically (I presume some sort of a protection of the compressor maybe?). So that makes it even worse now with the summer coming at some point in the UK!

 

I've seen people mentioning here that if it's not the blower motor, it could be the climatronic control unit - does anyone know if the control unit is the little box stuck to the back of the blower motor itself (this)? Or is the control unit the one on the dashboard where you control the speed/temperature from (this)?