Proper coolant temperature gauge operation?

[jer1303]

I know some cars come with a "dummy" temperature gauge - our Avenger did; but AFAIK most Fords come with a gauge that will read/display the temperature in a somewhat linear mean. Here's my question, I guess:

During warmup, the gauge gradually goes from cold (under the C) to a good spot a little under the middle of the gauge. Engine is defintaly hot and air from the heater is good and hot too. During this summer, while tinkering with the van, I had a few chances to observe the gauge while the engine was idling at operating temperature.

The problem is, I don't think the gauge moved at all (or very much) from the time the fans turned on to the time they turned off. It just seemed to hang in the same spot. This worries me a bit, because if it dosen't move how am I going to tell if it's overheating? With my old SHO's, you could see the gauge sweep during cooling fan operation.

Is this normal? Any input and insight is appreciated. TIA

[garync1]

As far as Gauge reading on my 2001 mine runs around 3/4 to the hot.. It did not move much as well once at operation temp.I do have a scan gauge and the hottest temp I have read with AC on in stop and go traffic was about 203 but for the norm on HWY the temp ran about 190's + degrees. But as for gauge needle movement mine does not move around as much compared to other cars I have owned.If it does its very little..

[wiswind]

Unless they changed this from how it is on my '96, you have 2 temperature sensors.
1 is for the dashboard gauge ONLY
The other is for the PCM.
The value that is being read by the ScanGauge, which is connected to the OBDII port, is what the PCM is seeing from the "other" sensor.
These 2 sensors are right next to each other (I show them in one of my pictures), so the temperature at that point is going to be real close between the 2 sensor.
So, in short, if the reading on the ScanGauge is constant, then that is telling you that the dashboard gauge is correct.

I have also noticed that my vehicle stays pretty steady.
It may move a bit when stopped, but if it swings very much, I turn on the A/C, which forces the radiator fans to stay ON at low speed (If not on, check your low speed dropping resistor), and that keeps the engine cooler.
It also keeps the transmission cooler.