i have a yamaha fz 16 n i have this problem?

[Vishal S]

hey guys i am having problem with my speedometer it has not been show me speed since past 2-3 days..its stuck at 0 some times it starts working.. but its shows ny random speed.. i got it checked with yahama they said they will have to change the wire(sensor)...which is for 470 rs :s... now like today even the trip meter stopped working..onli my rpm is working fine!.. when ever i touch the wires below the meter the speedometer starts showing some speed ..plz tell me what shuld be the problem..i don want to spend 470 rs on tht shitty wire