[Melonhead1102]

What temp is the coolant running at? If you don't have a monitor in the truck, is the temp gauge getting up to the 210 mark, give or take?

If the truck is getting up to temperature, then I would suspect your internal temp sensor could be on the fritz.

 

[Melonhead1102]

I honestly can't remember where that's at. You could also have a problem with the heat/ac control unit too.

 

[Melonhead1102]

But that's your external temp sensor.... there isn't one in the cab?