(Manual) dash vents don’t blow air

[vegt]

Hi, I checked other threads but didn't come across one covering this scenario.

My dashboard vents don’t blow on this setting:



When in this setting, air comes out the windscreen vents and the side vents on the dash, but nothing comes out of the vents facing driver and passengers.

The other three settings seem to work fine for both hot and “cold” (it’s a basic Startline so no aircon) on all four speeds.

It’s probably worth noting that it’s a bit difficult to engage the dial into this position; it requires a bit of force before it pops into place.

Do you have any ideas? Could something be stuck somewhere?

Thanks in advance!

 

[Ads_Essex]

These heater dials control flaps via cable, so it sounds like a cable has worked loose or the dash flap(s) is broken

 

[vegt]

These heater dials control flaps via cable, so it sounds like a cable has worked loose or the dash flap(s) is broken

Ah, that would make sense. Thanks.

I’ll try to find some info about how to access this cable.

 

[vegt]

I've not had much luck getting access to the heater dial cable(s). Is anyone able to point me to a guide that covers this?

 

[mmi]

Perhaps some help >here< - p.32.

 

[vegt]

Thanks @mmi and @Ads_Essex. I got access to the cables and can see one of them is kinked so it doesn’t slide into the sleeve like it’s supposed to (as shown in red).

 

[vegt]

I replaced the kinked braided cable with this solid-core one from eBay: Solid Core Heater Control Cable Replacement Part For VW T5 7H2819837C | eBay

All sorted now and the solid cable should prevent it happening again. Thanks again @Ads_Essex and @mmi!

 

[vegt]

Also, in case it helps anyone in future, this is how to remove the controls to get access to the cables:



I also removed the glovebox for easier access from the side.

And I found these two (T5) videos useful when trying to understand the fault:

 

[vegt]

Oh, and something else I just learned – don't turn on the ignition with this unplugged otherwise you'll trigger the airbag warning (which requires Carista/ODB/dealer to reset).

 

[vegt]

Okay, so I've fixed the control dials and I can direct air to the dash vents.

However, I've just noticed the middle two dash vents don't blow air (whereas the dash vents next to the doors now work perfectly).

Some searching suggests that a faulty motor is responsible for this (e.g. Front Center Air Vents - No Air), but I think/hope that doesn't apply to these manual heater controls on my base-spec Startline.

Maybe you know @Ads_Essex?

 

[vegt]

I just discovered a wealth of hints in this thread:

Air Vents not blowing forwards heater vents not working...

www.vwt4forum.co.uk

It seems the issue with my dead middle vents might be related to the cams on the other side of the cable I just replaced. Hopefully fixable with a bit of a fiddle!

 

[Ads_Essex]

Okay, so I've fixed the control dials and I can direct air to the dash vents.

However, I've just noticed the middle two dash vents don't blow air (whereas the dash vents next to the doors now work perfectly).

Some searching suggests that a faulty motor is responsible for this (e.g. Front Center Air Vents - No Air), but I think/hope that doesn't apply to these manual heater controls on my base-spec Startline.

Maybe you know @Ads_Essex?

I don’t I’m afraid mate. But keep us posted and good luck

 

[vegt]

Found my problem. For some reason, the dial doesn’t turn the cam the entire way.

I can move the cam by hand, but the dial stops short before the cam gets into position.

Watch 7zqraf | Streamable

Watch this video on Streamable.

streamable.com

This video shows the cam rotated clockwise as far as it will go (I did this by hand) - and all four dash vents work as they should. I then change the dial one position clockwise, and then back. The cam does not go back into the required position, so the center two dash vents aren’t opened.

I’m sure what to do next as the cable and the dial seem to be functioning independently of one another:

• When unattached to the dial, the cable can move the cam adequately.
• The dials go from 12-o’clock counterclockwise through to 3-o’clock without obstruction. (It probably needs to go to about 2-o’clock to get the cam in the right place.)

I wonder if maybe this replacement cable is the wrong length?

 

[vegt]

I do think the replacement cable might be too short.

The solid core cable that I used is advertised as being a replacement for either the red cable (temperature control) and/or the green cable (windscreen/dash diverter control).

However, the photo below shows the OEM cables where you can see the red cable is shorter than the green – by about the same length required to fully rotate the cam/pully!



I've asked VW parts for a replacement OEM braided cable to try my luck with.

 

[vegt]

Came across this very useful diagram of all the parts involved:

• My original cable that failed by kinking is part 36 in the diagram (see post #6) – this is known as the "defroster flap cable", part no. 7H2819835D
• The cable I've replaced it with is supposedly compatible with part 34 (7H2819837C) and part 36 (7H2819835D)
• The cam/disc that I'm currently having trouble with is part 7 in the diagram (see post #13)

 

[vegt]

I do think the replacement cable might be too short.

…

However, the photo below shows the OEM cables where you can see the red cable is shorter than the green – by about the same length required to fully rotate the cam/pully!

Well my new OEM braided cable arrived, and it’s shorter than the aftermarket solid core replacement! Which rules out the cable length being the issue.



OEM cable is fitted and I still have no air from the middle two dash vents.

 

[vegt]

Before giving up, I started fiddling with the white disc/cam (part 7 in the above diagram).



I unhooked that arm in the photo and now the blowers seem to work perfectly in all directions.

Does anyone know what this arm controls? I assume it has a purpose but things certainly seem to work better with it disconnected.

 

[vegt]

Okay, so the beige coloured arm in my previous post seems to divert more air between windscreen and dash.

With the arm disconnected, air still diverts between windscreen and dash, but the air is more powerful when the arm is connected and functioning.

My problem is that the white disc/cam does not move the beige arm far enough into position to fully activate dash blowers (the middle ones don't blow) – so I've disconnected the arm from the cam put it into position manually. This is where it will stay.

Position for dash blowers (see where the beige arm needs to be?):



Position for windscreen blowers (the beige arm should ideally be at ~90º):



Set up like this, I now have have all 4 positions on the dial working correctly, with the following exceptions:

* windscreen blowers aren't as powerful as they would be if the arm was in use
* dash blowers are always on (I actually like this! And they can be "closed" via the individual vents themselves anyway…)

I'm leaving it like this for now. Hopefully there's still enough power on the windscreen to demist it in winter. I guess I'll soon find out.

 

[LawsScott]

Hi there. Similar problem and beginning to look into it. Where about is that white plastic cam? I’m having a look but unable to find it yet. Any help appreciated