I found the Ambient Air Temp Sensor! 2008 ProStar...

[Waterloo]

(04-27-2017 )barf Wrote:  I thought there used to be a post on here of where that sensor was located. I posted where mine was, 09 Prostar, mine wasn't buried in tape like yours, and I find mine reads fine unless I'm stopped. If it's on the highway getting lots of air it reads correctly.

I know I have asked at least twice on the ProStar. But mine was just an inch off of the radiator base plate. I had to cut the zip ties that secured the harness to the frame rail and front crossmember to locate its shape under all of the electrical tape. It only read correctly after the truck had been shut down long enough to cool off, and only in the winter. In the warmer weather it picked up the heat off of the asphalt, and that through it off. Now, it is reading the correct temp.