test procedure/yam. water temp sending unit?

[Capt. John Deering]

i have a stock water temp sending unit (orange background) it only has dash marks for the cooling temp., not numerical. ptoblem is when you turn on the key the needle does move some, not much. after warm-up it stays in the same place. tested the gauge by disonnecting it from the two harness at the motor, and shorted the wires back to the gauge together...the gauge pegged which should mean the gauge is ok.

used an ohm meter between the two wires going to the sending unit (which is mounted top side of motor starboard side) it showed "0" no resistance.

anybody know the yamaha test procedure for the gauge and sending unit. the shop manual does not say or i can't find it.

[Capt. John Deering]

what happened to the yamaha techs?