Water temperature indicator (or sensor?)

[nojapan]

Hello Folks!
Happy 2023!
I have the water temp indicator always showing 120 deg C in any condition, since I am turning on the key.

Is this a common problem?
I wasthinking to the indicato at the beginning, but a friend suggested to replace the sensor first.
Do you know if there is a cross reference to find the right sensor?

And if there was a switch for the fan that would turn it on at a lower temperature, that would be better.
Thank you all for any proposal!

[Mc tool]

Take the wire off the sensor and turn on key ......if the gauge still moves to 120⁰ it aint the sensor.
There are a few reasons why this thing could be playing up so dont get tunnel vision