Coolant gauge issue

[Robertl]

So I have a p0118 ect voltage high and my temp gauge does not work. I use my scanner and view live data and it shows proper tempature between 185 and 195 according to fans on and thermostat. And when I unplug the sensor it shows -40 but as soon as I plug it in it shows proper temp. I know its proper temp cause after a overnight of sitting I checked the temp on scanner key on engine off and showed 79 I did same thing on roommates car showed 77 so I'm sure the sensor is good. Now main problem my temp gauge always stays in the position of the pic I'm posting. I unplug the sensor and the gauge satays the same after a hour of diving the gauge is same even if I let it sit overnight as soon as I turn key on gauge is moves to tbis position and stays

 

[Robertl]

As you can see I put almost 7 miles on it and gauge still in same spot. Never moves unless I turn ket off than it drops to 0

 

[bavarianblessed]

What year? The 98-99 are fed from the thermo sensor under the distributor. The 2000-02 are driven by the ECU. It sounds like the gauge is just going out though, they are pretty easy to replace if that's the case.

 

[Robertl]

She's a 01 2.3 f23a1

 

[Robertl]

But if it was the gauge wouldnt it stay there even when the key was off?

 

[bavarianblessed]

But if it was the gauge wouldnt it stay there even when the key was off?

Maybe? The gauge is just copper coils and a magnet with resistors attached to the poles. It's hard to say what the issue is though, I would look at the caps in the ECU and on the gauge cluster board. They are almost 20 years old now and could be failing. Just a guess though

 

[Robertl]

I was just gonna put a 98 sending unit on the head and run a wire straight to the yellow green wire on the cluster

 

[Robertl]

Curious I have 2 extra gauge clusters but not sure if there 98 to 00 or 01 to 02. How can I tell the difference?

 

[Robertl]

I only wanna swap the temp gauge nothing else

 

[Robertl]

Update: plugged in dooner cluster verified gauge works. Swapped gauge to my cluster now it reads maxed hot when key is on