Noob question -- 2001 Path temp gauge

[dpsw]

Hi all.

I have a 2001 Pathfinder and my temp gauge stopped working. Once in a while it comes up to where it should but the majority of the time it just sits at C.

I've read guys talking about sending units and I wanted to see if I could diagnose this one myself. I'm a total noob, though, and I don't know where to start. If I could find it I could put a meter on it and see if there's any signal coming from it. Then I'd just have to replace it, which would be another question!

Thanks ahead of time.

DW