Reverse light switch? ETC, ETC

[93type-x]

Ok so I tried all sorts of things to cheat my road worthyness test ,,, but I really do need to fix my reverse light.
1) So what of the many plugs is it?
2) And where is the speedo sensor ? as mine tends to do its own thing...
3) AAAnd does anyone have a wiring diagram to show the speedo sender line to the ECU? please??

Cheers Si:Hammer

[tinker-27]

the speedo wires are yellow/red(feed to speedo),yellow/white,they are located in conector x,14 behind the heater box ,i have the reverse lights wiring somewhere if you need it cheers craig