So i got one of those for 4 dollar bill.
I remembered to bring my fluke home so I checked power across the grey and tan pins.
Grey was cool, tan was dead.
I yanked the seat belt shroud off and checked the plug under it to door.
All was good there.
I pulled the boot off the run to the door and the tan was cut. Just like someone took a snips to it.

Strip, twist, solder and heat shrink later the stock latch works.
Lotsa fiddle fckn around