Weird heating issues on mk1 not sure what's wrong.

[lockey1995]

So Ive only just got around to looking at it as I could really do with not freezing now driving to work lol. The first thing I've done is removed the glovebox and the pipe that goes across I've replaced all the foam there as it was missing or broken I've done the outside of the white plastic and inside the pipe.

Now I've done that my footwell heaters are red hot now after the car warms up but the rest are cold/lukewarm, for the window heater the driver's side blows quite warm and you can feel it but the passenger side you can barely feel it blowing at all. My diverter that that controls the different settings does seem to be a little sticky so I'm not sure if it's not opening fully the left side it won't click on that at all unless you really force it over. The other options work but it definitely feels there's more resistance compared to my friends car.

Any ideas? I'm trying to avoid taking the dash out of i don't need to im a bit lost now so could do with some advice of what to do next.