Why is my temp gauge not working

Any ideas out there why my coolant temp gauge is working when the coolant temperature censor is pluged in:confused:

Guage? sender? wiring?

This is usually caused by a bad sending unit, or the wire/connector going to it. If you have an ohmeter you can test the sender, it should read somewhere around 500 ohms(anything from 400 to 7 or 800 its probably good). You can check the dash gauge by unhooking the wire from the sender, use a jumper wire to hook from the wire to ground(preferrably one with alligator clips, make sure you have a good connection and good ground. Now momentarily turn the key on, and back off. If the gauge moves, its ok. (be quick and dont let the gauge peg out, it will move rapidly) The gauges seldom go out, its usually the sender or wire. Make sure the wire is good and tight on the sensor stud, sqeeze it together slightly with pliars.