Definitely get a good schematic from a Haynes/Chiltons type of book, if not a Ford one. I have an '87, and it took a good deal of reading to find a schematic that matched my car specifically, so it seems there were changes throughout the model years that go beyond just adding things such as airbags, etc.
I reused the factory ignition switch, turn signals, hazards, brights, etc. (don't know why I did, honestly) and it was kind of a pain in the ass. I wired mine to start by momentary switch, but to still require the key be inserted and in the run position. Draw it all out and be patient. Take pictures of the mess behind the cluster and on the column and photograph as you go. It will save your tail if you get a little lost or sidetracked and can't get back to it for a while.
87 coupe | 408W
Verde Ithaca Mica (Lamborghini Pearl Green)
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