We were having trouble with the temp gauge in my dad's 97 not reading , at all , he had it in the shop for some other work , and mentioned the temp gauge working intermittently, IIRC they replaced the sender , and called it fixed. I had his truck out for drive tonight, the the temp gauge is reading 90 (that's the half way mark on a metric truck) after driving less than a couple km's, in town, and the gauge stays up there , instead of cycling like it used to with the thermostat, and upon more driving , the temp gauge continues to climb... , this is driving around town , ambient temperature is around 10 degrees ( that's like 50 or so for you fellers). Any suggestions here?

 

Check the wire and make sure it is hooked up. The sender may be bad out of the box. Check the resistance of the sender cold then hot and see what it reads.