I was driving to work this morning through deep snow. The temp gauge was working fine, then a minute later after i last looked at it, it was down at 0 degrees. I restarted the truck, and the gauge still didnt move. Before i left home i disconnected and reconnected the battery cause my four wheel drive was stuck but i dont see why that could cause this. Any help is extremely appreciated.

 

Probably the guage in the cluster is my guess. You did not say what year it is. In models before 98 they have 2 sensors. One on drivers side head, i believe controls pulses for fuel injectors, other in front of top rad hose on motor, i believe it is for your guage inside. In 98 they only have one under the hood, on drivers side head. it controls both functions. My girlfriends 97 blazer would only come up to about 120 if you let it run all day long. Just swapped cluster & took care of the problem. Goodluck