Incredibly dumb question..Trans pig tail
That particular harnesses was retained by two clips on the transmission.
The longer one goes under top left tailshaft housing screw head.
Shorter one top right attachment bolt to engine.
If not on the car now, you can make 'em yourself or buy 'em. I made the shorter one.
Hopefully you dont have to do this but if you do...
One way to extend the wire is splice in a length of brown insulated wire.
Since I had female terminals for the connector, I replaced the terminal so only one splice junction was needed.
In fact M&H used the exact same Packard 58 terminal that I recently bought.
I opted for a tin plated version since its in the engine compartment.
Join the new wire with a crimp splice and heat shrink.
Location is pretty safe from oil, so I opted for the adhesive lined over the oil and fuel resistant type.