3.8L Buick v6 in a 1985 Oldsmobile cutlass supreme. Recently bought the car with the coolant temp gauge not working, there are 2 wires going to the same coolant sensor in front of the engine, which looks like it has been replaced before. When the wire from the gauge is grounded the temp gauge goes to full hot but never comes back down to cold or lower than full hot. Bought a single blade sensor and grounded the sensor with the wire connected and the needle did not move, the resistance from the blade to the body of the new sensor is 3000ohms at cold (room temperature) but still has no affect on the gauge. Anybody have any experience with this? Any input is appreciated, thank you!