Outside Temp. Sensor

Does anyone know where the outside temp. sensor might be on an 05 Expedition?

When the car is first started the temp. reading is correct and will stay that way untill the car is driven. Then after a few min. on the road the temp.reading starts to rise. It will go as high as 103deg. I am not sure if the sensor is bad or just loose and I have no idea where to look for it.

It should be behind the grill, in front of the radiator.

In front of the radiator. Look for a wire loom the goes to a sensor that has a plastic nub about .5" long. It will be mounted by a plastic push in, under the upper tie bar, on the center support or maybe even on the bumper reinforcement bar. Somewhere in the vicinity.