Jaguar Repair: 1984 XJ6 heat, rust repair, salvage yards

Question
Howard,
Please understand I was not offended by you not wanting to go through the whole system, and I wasn't asking you do do so. I try to only ask short questions of you, so that I may work through my own diagnostics techniques and I feel maybe when I simply asked what two objects were, just a confirmation from you, to identify them, that you wouldn't even answer that, at first. Of course, I understand your position, as on a smaller level, I am the family/friend mechanic and I am sometimes asked to diagnose problems on makes/models I am not familiar with by phone or email and I simply cannot without at least having the vehicle in front of me. Thank you for the help you provided, and the diagrams. At this time, I have determined the control unit to be jammed, and it may have been damaged by a previous hack mechanic attempting to fix, as some gears were even bent when I got the unit to the bench. For now, I have manipulated my heat system to offer heat at low and high fan settings, but replacement of the control unit is quite expensive as you must know. I think I'll revisit that later, and tackle rust repair as a winter project, so you won't hear from me for a while until I once again find myself stumped, which I hope is no time soon.
Thanks again,
Michael

Answer
Most of these parts can not be found in the aftermarket so buying them from Jaguar can run higher than the car is worth. But fortunately these cars can still be found in salvage yards so used parts can often be found. And another good thing is that almost everything for the heat/AC is mounted on the box so sometimes you can get the whole box at a reasonable price.
Howard