asuming that it is a manual gearbox there has to be a switch on the gearbox somewere have a good look round maybe the wires have broke off it and you dont recognise is as the swich.
look for a wiring loom near the gearbox if you find it cross the wires and see if the reverse lights work
lee
April 2008
should be fuse 8 in the fascia fuse board which is situated round the steering columne area
ash
April 2008
I can answer this question...
How can I fix the non-functioning reverse lights of my 1997/8 Nissan Almer?