Temp gage problems?? I think...

[5LZEATR]

I have a 99 2 door hoe with the 5.7 of course. I'm having trouble with the temp gage. As soon as you start it up the needle on the gage goes to exactly halfway between 100 and 210 which should be about 155. It goes there as soon as you start it and it stays there no matter how long you drive or let it run. It heats up and the heater works fine. It hasn't overheated either. I have disconnected the temp gage wire from the sensor (on the head) and the needle goes counter-clockwise to about what would be the 7o'clock position on the temp gage. Guess what I'm asking is the problem the sensor or the gage? Is there a way to test the sensor with a multimeter or something else? Is there some way to test the gage itself? Thanks for the help in advance.

 

[5LZEATR]

For those of you who might be interested, all 9 of you, I changed the sensor today. The gauge now starts out at about the 7 o'clock position and does move clockwise as the coolant warms up. So the sensor was bad, now I have a new problem. Is there some type of calibration to get the needle on the gauge to start out in the right place? When you turn the ignition off, the needle goes up just below start of the numbers on the gauge, where I think it should start out at when the engine is cold. As soon as you turn the key to the run position, the needle drops down to the 7 o'clock position. Someone, please help

 

[willua11]

Were you burning off/losing coolant? Mine warms up like normal, but only goes to halfway. I am going to pressure test it soon, hopefully.