I have several coolant sensors that are bad, ebay brands, Amazon brands, and yes even brittpart. The resistance reading of the thermisters are all different, and some of them are even pinned out incorrectly. It's likely the sensor.

 

Since I last posted the ultra gauge has stopped reading any temp at all which is interesting, just blank. Once I figure it out I’ll post it here in case anyone has this issue down the road. The sensor in it now is all makes I believe. Came from lucky8 or AB. It’s all hit or miss I guess.

 

I have only had one fail but have long ago converted to non-lr external temp gauges.