I'm sorry to say that I don't have any wiring diagrams for that year. The alternator's circuit will have one (if not two) fusible links in its circuit... 85's have two. Locate them and test for voltage drop. They're most likely the old style which just looks like thick insulated wire, they're not and don't try replacing them with regular wire. Over time the insulation often crumbles and the wire becomes exposed and rots away.
The next places to test would be the EFI fuse, Gauge fuse and wire harness.
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