Misting up

[Mcgoonagall]

Hello all, I'm hoping someone can point me in the right direction here.

I have a 1990 (pre-facelift) XJ-S 3.6; amongst other little foibles, the aircon works fine (no, really!) during the summer albeit, at the end of a run during the warm weather, it puffs out a little condensation on the windscreen, on the passenger side. Only a little, and something that a friend's XJ-S does too (so I assumed "they all do that").

However, now the weather has turned cold, every time I use it, I get a lot of misting up but only on the passenger side no matter how long I run it for or what setting are on the controls. Setting it to demist seemingly makes little difference. It is not dripping in condensation (I have a moisture trap in it now when it's tucked away in the garage - it also chucks out plenty of heat in all directions on demand and is not leaving puddles of water in the footwells!) but when driving, it is getting to the point that the passenger side windscreen and side window are completely opaque and, frankly, dangerous to drive with.

I'm hoping someone will immediately know what it might be - and thank you in advance for any help/advice/soothing noises anyone can give!!!!!

[davidr]

Is the drain tube on that side blocked? It may be that it's partially blocked so it drains but slowly so it doesn't overflow but there's moisture there to be pushed up onto the screen.
You can check either by pushing something up the drain tube from below or taking the cheek piece off the side of the centre console and checking the drain tube from there.
Another thought is that maybe there's water in the passenger side fan casing? Could have got there from the scuttle drain?
Hope that helps
Regards
David

[Mcgoonagall]

Thank you David for your thoughts. I'll have a dig around as per your advice and see if that sorts it!

Thanks

Martin