Factory wiring question

I can start the car in any gear and I have no back up light. Before buying a new expensive switch, I wanted to see if someone had just bypassed the system. I've seen that a few times on this car, wires not fully understood has been cut and new wires fabricated. Can't really blame the Italian mechanic trying to fix the car with no wiring diagram...

When looking under front left carpet I found 2 wire sets just laying there, cut. I can't find them on my (Deauville) wiring diagram. They come out of the tunnel just in front of the parking brake, but it's not parking brake wires because the parking brake warning light works. Can you tell me what these are for (and where I find the wires to get the intial problem mentioned at the top solved)?

1. wire set:
Brown________thick___Constant "+"
Green/Yellow__thick___Ground

2. wire set:
Green________thick___Ignition "+"
Orange_______thick___?
Brown________thick___Ground
Brown________thick___?
Red__________thin____?
Red__________thin____?


By the way, looking for the starter wire, the Deauville diagram says pink, but I have blue and brown wires on my starter relay?

Thanks