Change to 4-lever heater box controls

[Enzo79]

Slightly odd question, but have just bought a Syncro Doka... which has all the interior stripped out, and whilst it has no headlining I noticed the holes in the metalwork where the vents would normally sit in the roof area of a higher spec vehicle, and was thinking about adding them, especially as I don't have any opening windows in the back.

I had a look in a friends Caravelle, and the roof vents are fed by air that is fed from the blower, through the cab doors and then up inside the B-Pilar. The Caravelle has the heater controls where they have 4-levers, and one seems to cut off the flow of air to the roof vents.

Is it possible for me to retro-fit the bits to get the air flowing from the outlets infront of the doors, as no air comes out of these at the moment.

I did try and look on the parts catalogue to see what bits were different, but couldn't see any differences with the heater box, only with the controls themselves where they all the new replacement ones came as 4-lever, but with a note to remove one lever if being used on other models.

Is the extra flap in all the heater boxes, and is just left in the closed on the models that have the 3-lever controls.

Many thanks in advance.

[pirate-pete]

No fourth flap on mine but can't remember if there was any mounting lugs for the shaft or other gubbins if you cut out the panel where the flaps would be.

What I did notice though on my van was that the crossmember the heater box sits on did have the cutouts so if I had the correct heater it would pass to the door channels and to the b-post. Have not checked behind the trim above the windows to see if the roof level ducts are there. Have seen piccies of other vans and that front crossmember is sometimes solid under the heater.

Could be mine is passenger body rather than panel van conversion.