Temp Gauge on Hiace with 4Y engine

[cat007]

Hey all

My newly purchased Hiace has something strange going on with the temp gauge

After starting the engine or even just turning the ignition on, for about 15 seconds - the temp gauge instantly shoots up to half way

The only movement I've noticed is after a long drive on the motorway the gauge will drop to about 1/3

If I unplug the wire to the temp sensor - the gauge still sits on 1/2.....

Maybe there's a short somewhere? Or??

Any thoughts?

Cheers