dash temperature sensor

[ilikeching]

Hi,

my 'dash interior sensor' on the passenger side vents runs(the fan inside sensor) even when i leave the keys out, and it have drained the battery over 2-3 days not using the car.
I have unplugget this unit and the car/battery works fine, its not draining the battery, and the air con heater works fine.

Does any had similar problems?
Thanks

its a 97 model.