It's impossible to work on these cars without accurate information. It's true for most cars, but especially so for the Scorpio. Some of the components weren't used on any other US vehicle. A similar motor and transmission were used in the Bronco II and Ranger.
I recommend the factory manual 1) because it's over a thousand pages of the exact information you need for maintainence, and 2) there's no consumer-level book that is correct for the US car. The European Haynes Ford Granada/Scorpio manual is different and lacks coverage on US-specific options like auto climate control.
The factory material consists of the main book, the EVTM (Electrial & Vacuum Trouble-Shooting Manual), the wiring diagrams, various other more specific electrical and specification manuals, and successive service bulletins. The EVTM is about 150 pages (which is a real time-saver), and the several wiring diagrams fold out to a couple of feet.
Helm, Inc. offers an array of the factory books at factory prices. Lately (fall 2006), there are CDs of the factory book in eBay for less than $10.
Alldata offers a subscription service for information, basically consisting the whole EVTM and a huge pdf file of all the factory service bulletins (which justifies the cost on its own- *many* fixes unavailable elsewhere).
The Mitchell repair manuals used by repair shops also seem accurate, as far as they go. The factory book (on one car) is about half the size of any Mitchell book, which consists of all the foreign or domestic cars in a particular year. All the wiring diagrams are printed, though at about 1/3 scale.
Here are several pages of parts listings, mostly exterior/body repair stuff. It's a .pdf, and it's 8 meg. Right-click the link to download to your machine, or left-click to open in your broswer.