Bad temperature sensor??!!??

Hi i ve got funny problem, my temperature never goes more then 1/3 of the scale
and its usually just above the cold mark and does not matter how long i drive...well it used be exactly on the half...

so is it bad temperature sensor?
addition, engine dont seem to be cold at all, fans turn on if im on parking with engine on for about 3-5 mins and thermostat was changed less then a year ago...

so how can i locate the temperature sensor and any way to check it ?? ( yeah i've got voltmeter and some skills )

cheers