Reverse switch is located on the top of the gearbox inside the engine bay. It's hiding a bit but is visible, it's usually white and is located by the side of the cylinder block, look for the hydraulic piping going into the box on the top and it's right next to that but slightly lower.
[IMG]http://img.photobucket.com/albums/v451/Oddjob323/DSCF0202.jpg[/IMG]
This is it
19mm spanner needed IIRC.
Ken
October 2006