Here we go again. Ford's harness suppliers used a non-adhesive vinyl tape, not friction and not your run of the mill store bought electrical tape. 3M was one supplier Ford used. 3M recommended Temflex Flexible Insulation 2585 as a reasonable substitute. There may be newer products today. I got my roll about 20 years ago. The ends were tucked back into the wrap, no glue or adhesive was used. You can see a "pigtail" sticking out near the an end.
On the other hand, I've seen a few instances of friction tape on the ends of harnesses and assume it was an assembly line "patch".
Jim