85 cougar engine harness

Have you looked for a 3.8 harness out of a mustang of the same vintage? It should work as well.

Are you missing the whole harness?

Oh geez. I’d say car-part or junkyard scouring might be your best bet. Most junkyards don’t keep anything that old anymore so you’ll be hard pressed to find one. Another route would be from a mustang. Four eyed pride mustang forum might be another source.