T 5 vent control knob fix

[Julian Edgar]

This may be well known but I couldn't see it anywhere.

1) Bought T5 cab chassis

2) Found vent control knob defective (the one that directs air at face, floor, etc). It wouldn't direct air and made awful 'broken' sounds as it was turned.

3) Pulled out assembly (the two knobs plus air con and recirc switches form the one assembly). Note: be careful when removing the control panel - the control cables must be unclipped from the back of the panel by rotating their plastic clips. They are easy to break.

4) Looked long and hard at the vent control knob and its mechanism. Observed that the vent control knob has a toothed cog that engages with another that in turn rotates a cam plate into which two sliding pins insert.

5) Realised that they two cogs are designed to stay in register with one another, and this is achieved by a rather nice change in tooth pattern on each of the cogs. When in register, the altered teeth mesh smoothly with each other. However, if register has been lost (the cogs are no longer in the correct rotational alignment with each other) the control knob makes awful sounds and doesn't rotate the other cog correctly.

6) Fix is to place the cogs back into correct register, achievable by some temporary bending of the mounts and judicious slipping of the teeth past each other until the 'altered teeth patterns' line up with each other and so both rotate smoothly through 360 degrees.

7) Final step is to use Vaseline to lubricate the cogs, the cam plates and the heater box cam plate (accessible by removing the glovebox) so that the forces acting on the heater control are not so great that teeth slippage occurs.

System now works as new.

[Rebuild]

There is a fix for the heater cables here, with pics.Not quite the same issue.
How to fix your heater cables [improved!] - The Brick-yard

but thanks for the info.
I'll need it when mine goes

[SnowMotion]

Thanks Julian,
I hope to see more of your usual problem solving applied to the VW T5.
Always enjoy reading Autospeed and previously Zoom. Zoom was still a reference tool when I took to modify my first car a Nissan NM35 stagea.

[Baytown]

Thanks for this. My control knob is also stuck with only the two end vents working. It must be directing the remanding air to the windscreen.
I did pull my dash apart and was advised that the wire cables are notorius for kinking (my van is a 07). I couldn't find any bent or crinked cables, and did lube the dials and their gears with silicone. Still stuck on the demister setting.
I'll wait till Ive got the tolerance to pull the dash apart again and check for your fix. I believe the fault started after the car was serviced one time. Perhaps some one was ham fisted with the dials.
Thanks again.

Ken

[Sunny43.5]

I think you will find that the inner wire cable has corroded as the outer is a flexible steel almost spring looking thing metal on metal not a good combo , I found that it was necessary to try and get lube into the inside of the two before smooth operation is had .