For the record I have the 5.9L, ha.
I'm talking about the one behind the alternator to the left of the thermostat, it is loose and wiggles around, i pulled it out and it has some corrosion on it so i'm guessing that's why it is failing. Should I try to clean it off or just buy a new one? And where could I buy it at? ha

 

Replace it, with the one I gave you the # for, or have the parts store of your choice cross reference it. And it better be a 5.9 gasser you have. LOL

 

Alright thanks for the help, and yes i forgot to mention it is a gasser! haha