Do you have a volt meter?

 

Sounds like I need one. If it helps solve this problem I'm game.

--tj

 

You can unplug that sensor again and see if the original gauge in the car remains at the cold setting.

A digital multimeter cost ~$20 at places like Wal Mart. I got one on sale at sears for $10. You can borrow one from someone as well. They aren't too expensive.

To eliminate the wire as the problem, you need to unplug the wire from both ends. Meaning you will unplug the sensor in the engine bay and unplug the gauge cluster.

You will use the resistance setting (or open/closed circuit) on the multimeter. Touch one lead of the volt meter to the unplugged wire in the engine bay. The other volt meter lead you will touch to a valve cover bolt (ground). You want to see if that circuit is closed or open.