Outside thermometer 10 degress lower
 

My thermometer that reads outside temperature, the reading behind the steering wheel, has been reading around 10 degrees cooler than what it should. I believe the outside element is bolted to the front license plate.

I don't know if this has anything to do with it, but when I got it back after being painted, the guy did not bolt it back and for some time the wire has been dragging on the ground. I thought if it was broken, I would get no reading at all.

In any case, it appears to be off. What can I do to remedy this?

Thanks