gear box puzzler??

my brother was serviceing his fl 1.8 petrol 1998 s reg no hill descent etc and when the tray was off underneath the engine he noticed a sensor/switch at front of gearbox with the wires broken off,it isnt the reverse switch as we tested it and it is on top of box,so what is it???
cheers gus

Would suspect it was the first gear switch for if you had HDC. If its the same box then fitting the switch to do nothing is probably cheaper than having a different casting for the box or for a separate plug to fill the hole. Slap a DVM across it and see if its shorting when first gear is selected.