Coolant Temp Sensor

I have a problem with my blazer, no matter how hot the engine gets, it only goes up to about 160 degrees on the gauge. I have had the engine scanned and it shows no codes for coolant temp and reads about 190-200 degrees. Why such a difference in what the gauge shows and what the computer reads? What can I check to make sure what part needs replacing?

Since the reading depends on a resistance change internally in the sending unit (2 seperate senders) , you may have corosion on the wiring harness . The dash instrument sending unit is under cylinder #2 or passenger side front on the engine block . Rob

I had the same problem last week. Low reading on the dash board (it was barely 2 divisions from the bottom) and scanner reading above 190. It makes no sense but replacing the thermostat fixed it. I would expect a low reading on both sensors if the thermostat was bad. But that was not the case. A check of the thermostat in a pot of water on the stove did show it opening about 180. I have not yet rerun the scanner temperature. THe dash board guage is again sitting at its customery place of 2 divisions below the center mark

i replaced both the temp sender and temp sensor, they were fairly inexpensive. Still have the same problem where the gauge only show about 120-130 degrees when fully warmed up.

i must be backwards, the guage on my 94 is digital and reads about 215-230 computer is reading it at 190-200