Here is an exact situation. In the cold morning the reading is 40 degrees at 6am. That's correct. When the sun heat things up, it would be 65 degrees actual at 9am. But the reading is like 45 degrees. This is after the car is warm. This is going to work.

I know reading can will all not be accurate. but 20 degrees difference is way too big.

Therefore, my question is, where is the temp reading sensor located? Could there be a pocket of cold air that is preventing it from reading the correct temperature.

The hard part is when I go home in the afternoon. The temp would say 70 degrees. And maybe move up or down a few, like how it suppose to be.

This only happens in the morning when it's cold side.

Summary: Morning - temp reading always off by a lot. Afternoon - Correct.

 

the sensor is attached to your driver side headlight bracket, when looking from the front it's on the bottom left hand side.

 

You have to drive for about a mile before it gets the proper air flow to make it read correctly.
Mine does that too after its been sitting for a while.