Changed the CTS now temp gauge won't move. Could this be the thermostat?

What is your question?

Just bought a brand new sensor put it in and now the temperature gauge isn't moving at all. Checked voltage from the wiring and it's good, and checked the sensor for Ohms and it's good. Could it be the Thermostat? Also the fan now runs nonstop where as before I changed the sensor it would never come on.

What makes this problem better or worse?

Seems to be shutting off once it gets too hot.