Lighting problem

[Lurch]

This isn't a situation where guessing at whether the black wire was connected and where it may or may not go is a good idea.

The whole thing is a mess. It needs to be pulled apart and terminated correctly, which will involve using some test equipment.

 

[binky]

that's a fiddly mess all right. Might be worth lifting floorboard above light and see if you can release some slack on the cables.