Was starter turning over when solenoid (starter relay on inner fender) was smoking?
Check Fusible Link between the starter relay and alternator
Bad FL pic Ron Francis via Ryan M (Fireguy50) at http://oldfuelinjection.com/files/fusible-link-blow.pdf
Bad Fusible Link pic & depiction; "...most fusible links have melted/charred insulation when they burn out..." by miesk5 at http://fullsizebronco.com/forum/showthread.php?t=181223
see more including:
pics by shift1313
here are some pictures i just took. the first two pics are of an 89 5.0. because of the loom i wasnt able to trace the wires for you. The second pic is at the starter relay to show you a fusible link wire(the green wire in my fingers you can see at the eyelet there is a black plastic block). the third pic is of my 85. i think that big block is another style fusible link ford used on older stuff(but im not sure).
Wiring Diagram in an 84 Bronco & F Series Section 2
Source: by Chilton http://content.chiltonsonline.com/co.../85766114l.gif
Location in Wiring Diagram for 84 Bronco & F-Series; "...Similar to 80-91 Bronco
Source: by Steve83 (Steve, That dirty old truck)
A, B, C, D, E, F, G ,H, I, J, N, P, S Locations in an 83
Source: by Seabronc (Rosie, Fred W) at http://broncozone.com/index.php?app=...ttach_id=11372
Repair & Color/ Gauge sizes; "... Fusible link wire is normal wire with special insulation designed to contain the heat, spark, and melted metal when the wire burns from excessive current draw. Fusible link wire is not rated in Amperes since its characteristics are less-obvious, but it is typically 4 gauges (AWG) smaller (higher number) than the circuit it protects. Although many vehicles now use MEGA or MAXI fuses where older vehicles used fusible link wire, replacing older fusible links with fuses is not recommended unless the rest of the wiring is upgraded to match the newer arrangement. Never replace a fuse with fusible link wire. In an emergency, smaller-gauge wire may be temporarily substituted for fusible link wire until an appropriate repair can be made; Orange - 22ga. - 0.35mm; Gray - 20ga. - 0.5mm;
Blue - - - 18ga. - 0.8mm; Black - 16ga. - 1.0mm;
Gray - 14ga. - 2.0mm; Blue - 12ga. - 3.0mm;
Orange - 10ga. - 5.0mm; Black - 8ga. - 8.0mm..."
by Steve83 http://www.supermotors.net/registry/media/830776