Cabin Heater

Evening all,

I have an '83 Tintop and have a bit of an odd problem. Since I've had the car the vents inside have blown hot air. I took the dash apart and figured out that the cable attached to the heater control valve opens to hot and doesn't have enough tension to close again. I've manually closed it under the bonnet so I have cold air coming from vents next to the mirrors at either side of the dash. The odd thing is that the lower vents and the smaller vents at the top of the dash still blow hot air. Ive traced the pipes through the bulk head and into the heater matrix. Can anyone enlighten me on how it all works please 🙏

Attached a pic of the pipes coming in to the matrix to support. Only one has the heater control.valve on. Any help would be amazing as im sweating my back off in there

The vents on the side blow cold air only that is how they were designed from the factory.

The center vents can go hot or cold.

There is a fix to blow heated air ot the side vents.

https://www.cabby-info.com/files/hvac/AddingHeatToSideVents.pdf

To fix whistling vents or vents that don't close fully.
https://www.volkswagenownersclub.com/threads/cold-hands-whistleing-vents.9898/?id=9898

Thanks Briano1234 I'll take a look at the links and report back!!