Sounds as though the engine overheated. You should look at replacing the radiator, because the existing one is probably clogged.
A trailer converter might be the best solution for the rear lamps. By the late 1990s I believe some of the lighting functions were controlled with electronic modules, and changing those would be a problem.
Keep us up to date! We're looking forward to seeing your progress!
I missed this 1st ime around.
Trailer converter would be bass ackwards - it converts separate turn and running/brake lights in running/turn & brake lights. I'm not sure it would split signal off...
What you need is someone with nefarious skills and knowledge"
a. You pick up a set of '93-'00 taillights with amber turn and red running/brake plastic.
b. You find a Canadian '98-'08 Mazda or '05-06 STX and you pull the wiring harness from cab back and the GEM. Mazda/STX tail lights won't bolt into regular Ranger box.
Canadian truck guarantees daytime running lights, those years/models would have the wiring/controls for separate turn/brake lights. (I would lean heavilty to years right around '02-05 to minimize harness/GEM differences.
c. You sit down with wiring guide and make sure all the wires are correct