Just this morning I noticed that the needle on the stock MR temp gauge wouldn't move from the lowest temp reading. This pretty much stopped working from one day to the next. Any ideas on what could be the problem?

 

Not a resolution but I've dealt with a similar irregularity for the past year on my car. I can be sitting idle and turn the A/C on and the gauge will slowly increase to peg out like the car is overheating. Turning it off it will go away, or when the fans kick on and off it will sometimes come back down. I have an AEM EMS in my car and can watch the actual temperature in digital output and it doesn’t chance at all. I've also put a thermometer in the coolant to verify temperatures. I’ve been thinking its possibly a grounding issue…

 

Weird. The problem seems to be resolved, at least for now. I decided to take apart some of the dash and look at the wiring of the gauge pack, and sure enough, it just started working. I wonder what the deal was?

 

could also possibly be a bad ECT, i have had issues with other vehicles with the gauge working sometimes, perfectly fine or not at all