The temperature sender for the Gauge is a brass device with a screw thread sticking out of it. Take a look at this picture,
Contour.org it's the round gold thing above the flywheel and 1/2 to 3/4 inch (on your monitor image!) to the right of the waterpump. If the loose plug is black rubber and is attached to a "white wire with a red line in a black sleeve" it would be for the temp gauge. Please post the photos. The other sensor is probably the coolant temp sensor for the engine computer, which is near the intake manifold and hard to see, and may not be bad..You might have fixed your car, except for the gauge.
