False hot temp reading on dash display.

:confused:
I have a 1992 s-10 blazer, 4.3 engine, z code. I got a dash display that has started showing 260 deg temp reading.
The thermostst is working, 195 degrees. The engine is not overheated.
I changed the temp senser in the intake manifold beside the thermostat. Started the engine the first time and
let run for 5 min or so. Temp 150 or so. Shut it off, picked up tools, washed hands and was going to make
a test run. When I started it that time, the temp showed above 200 degrees, and soon climbed to 260 degrees.
I got a thermometer and checked fluid and it was 140 deg. After an extended run time
I get the fluid to approx 195-200 degrees with a thermometer. The dash still reads 260 degrees.
I have disconnected the battery to maybe reset system, etc. still no change.
Is there another senser that I do not know about, or does the computer need to be reset somehow?
Thanks in advance.

Did the sensor you replaced have 2 wires going to it? If so, that was the temp sensor for the ECM.
Look on the left (drivers side) head between the spark plugs for a single wire sensor ( the one with the mushroom head is the knock sensor thats not it) If I remember right, it should be near # 1 cylinder....thats the coolant sensor for the temp guage.

The one I replaced had an oval socket with 2 prongs.
I assumed being that one was in fluid, that was for the dash.
I know the small blocks had theirs on the left
head near the front by the exaust port.
This sounds like a similar location.
I did not know there was more than 1 for temp.

Thanks.

The parts store called this one a switch. They say the senser controls the computer (first one replaced).
The switch controls the dash indicator. Mine was on the right side head between cylinders 2 and 4.
When I ask for a temp senser the first time, they gave me that item. The next time another clerk with
more experience knew to look for another item, a switch. Seems techinical but thats life.
Thanks for all the help.