What is this?? looking for temp sensor

[Snotty]

ok, i tried hooking a wire from the sensor on the left to the gauge and nothing happened. the gauge inside is at 1/4 but the other gauge hasnt moved from the bottom.

is there a way i can test the gauge to see if it works?

heres a pic of the back of the gauge,
Its a speco 2"

 

[vt1538]

It is a mechanical guage. Throw it in the bin as it is useless.