You dont need to be an electronics Guru to own a multimeter (VOM). Walmart, or any parts store sells them dirt cheap. No good excuse not to own one.

 

Thanks for the further clarification as to what was replaced. It'll sure help others if they come across this issue in the future.

I figured you were talking about the ambient temp sensor, but thermistor isn't really a good name for that sensor as there is also an internal temp sensor which could be telling the ECC module that it is 40 degrees inside the cabin as well.