I'd like to thank everybody's help in saving me $500 today. I had mobile service coming out tomorrow to replace this harness. Thought I'd swing by here and see if anybody had a solution. And sure enough!
I just cancelled that appointment.
So here are my pictures.
I guess that anodized ferrite core was keeping the wires insulated from each other? I didn't want to risk shoving it back on, so I installed shrink tube over my soldered wires. The core is just shoved up high on the existing wire, out of my way.
Because my connector completely separated from both wires, I took the connector back to my bench and easily added 5" of wire for extra slack. That made soldering it back into the car's harness much easier, without fighting the short wire.
I unbolted the seat so I could tilt it back. But I did not take off the rubber side skirt of the seat. It was a struggle to get the connector off initially. I used a small flat screwdriver to unclip/lift the orange thing by the side ridges. Once that popped up, the whole connector came off the seat. Then the yellow shell needs to be carefully snapped off. My black wire was already separated, and removing the connector popped off the OTHER wire too. These wires came off cleanly. NO fraying, nothing broken. The solder joint was just terrible. So I fluxed and tinned the tabs, and now that solder will not be coming off.
Error gone.
For those who have seen the error, and then it "went away." I predict that it WILL be back. Those connections are not up to the task. It is just a matter of time.