You will be unlikely to find someone on here to provide a link to a wiring diagram for your stair-lift.
Even if you get lucky you will not know on the circuit schematic which is the wire that's come adrift - where it comes from and where it goes to. An assembly drawing might help but probably not.
You have two choices - guess where the wire should be placed based on its length and termination - versus the places where it might reasonably go.
Alternatively call in a person experienced in the servicing of your Wecolator.
Good Luck...
June 2016