Hello all! I was just wondering if you could tell me how to tell if a thermostat is bad and in need of replacement? My temp gauge moves to just above 0 then stops.... I have a 1989 F-150, 5.0, 2 wheel drive. any suggestions would be nice.

 

Sounds like it failed in the open, better than closed. Or, do you know if it has one?

 

or..............the sender unit has given up.