I see the experts have not yet taken up your post but I can only say that there is info on here somewhere if you search the board. I have the same problem on my 2007 S type and never got it sorted since 2 years back.
I just considered it too much hassle and so ignored it.
I think the facelift is basically the same as the earlier delanair mkiii although access may differ.
There is info and pictures on the net, have a google for delanair mkiii and I'm sure you will find what you need.
For others watching, it's important to 'excercise' the various controls often to keep the bits moving rather then leave the settings in the same place all the time.
1988 3.6 XJ-S coupe
'Remember that the value of your investment can plummet as well as fall'
As commented above, the Facelift has the Mk III air-con, which is controlled by micro-processor. If you have the Jaguar Heritage DVD of "Supplementary Information", you should find a diagnostic guide for it; I wrote up my experiences earlier here in this forum.
1981 XJ6 Series III basket case
1991 XJS V12 "facelift"
2008 XJ TDVi