I would have thought that most of these features would be built into the GEM (timer functions etc). There's connections to the screen in both A pillars (one ribbon cable, one regular cable) which both go down the A pillars behind the dashboard.
I've pulled the relevant wiring diagrams for you.



To cut a long story short, it looks a total ballache to do it properly. You could bodge it by creating a new circuit (use a combination of timed relays, new feed from the battery, ignition switched relay and the Ford switch) in order to make it work bypassing the official method using the PCM and GEM modules.