My 2015 GMC Sierra 1500 5.3L has been running cool for a while. Temp gauge finally quit registering and the radiator fans wouldn't shut off even with the key out of the ignition. Pulled the fuses since I was at work that morning when this happened. Got a new thermostat (overnight shipped) and sensor from Oriellys. Must be a shortage because no one had one in stock. Anyway, changed both, topped off coolant, and had to unplug the battery to get the gauge to work again. Seems to be ok. I'll keep y'all updated if anything changes. Thank you all for the extremely helpful information. Saved me a chunk of change and a major headache. Happy new year to all.
