No I dont think its a thermostat issue...the gauge shows all the way hot, as soon as i start the car up, even after its been outside all night in below freezing temps.

I just went to Autozone and bought one sensor, when i plugged it into one of the connectors (there seems to be one at both coolant hoses coming from the radiator) the gauge still reads where it was.

I took a ohm meter and measured the resistance of the new gauge, and it shows about 1750 ohms to start, and as it heats up in my hand, resistance drops. Howver, at both the sensors in the car, it shows infinit resistance! Possible that both the sensors in the car are bad? I bought this car used so i dont know too much about the history of the car..

When i plugged the new sensor into the front plug, when i shut the car off, the cooling fan comes on. When i take the plug and put it back to the sensor in the car, it doesnt do anything.

Any ideas? Should i go back to the store and buy another sensor and change them both out?

Thanks!