Ambient air temperature sensor high voltage

[Waterloo]

Well, the temp sensor was wrapped in the wiring harness on the driver side by the hood hinge on my 2008 ProStar, under the radiator. There was a bulge in the electrical tape, that is how I found it, and it was not easy. I had been looking for that thing for over two years. Oh, the dealer told me mine was mounted in the mirror housing too.

If that is your problem, I really can't tell you, but it is a place to start. Find it in that harness, dig it out and run the wire. Check for breaks or bare wire.

Here is a link to Navistar Bodybuilder, http://bodybuilder.navistar.com/General/...s08339.pdf it has all of the electrical nonsense on your truck. I would start at the temp sensor on the schematics and work your way back to the ECM. I am sure it runs through any number of sensors and other nonsensical places. Like the compass module that my ABS brake system and Jake run through. I am sure it is the same with that Ambient Temp Sensor. I believe that is why you are getting so many answers as to what to replace. The schematics are your new friend. ;-) Good luck!