Some labels have fallen of my loom the neutral warning light an oil light share a wire but I can't remember if its Brown or black 

It's on a 1989 DTR but I assume otheryams  are the same 

The neutral an oil light share both share a wire but I m not sure if its An earth ( black ) or a live ( brown ) 

From what I can work out this wire comes from either the kill switch or front brake light switch ( on a DTR) 

Trouble is I ve replaced some wires an now I have a random black wire with brown tracer stripe that's not on the Diagrams 

So I need to know the correct colour wire the two warning lights share ? An where it should come from 

Don't forget the oil light comes on with the neutral light as a way of showing the bulb works properly.