Hey i'm having a problem with my 90 5.7L GTA, i changed out the coolant temp sensor and the thermostat yesterday because the gauge isn't reading the temperature at all it just sits at 40C, i have taken the car for a spin long enough for the coolant to heat up past that but still nothing, could it be the temp sender that is shot?

 

I believe the gauge reads of the sensor in the Drivers side head. The sending unit by the thermostat sends temp info to the ECU but the other device not sure what it's called sends temp info to the gauge in the dash. Instead of having a plastic connector that plugs in it actually clips on to a metal post on the end of the sensor.

 

so would i need to replace the sensor on the drivers side of the block then?

 

If it's plugged in and your not getting a reading on your dash then yes i would suggest replacing that piece for a new one.