I was wondering if somebody had a more definite answer, like a schematic
The pnematic/aircon "schematics" should be in one of your manuals, but it won't necessarily tell you where the components are. You would be better off with a few diagrams from the maintenance manuals.
In the maintenance manuals, there are diagrams showing the location of the overheat loops in Chapter 26. The aircon components will be shown in Chapter 21. I was using these to come up with my earlier deduction