Radiator sensor or probe?

I have a 1992 BMW 325is. The radiator is overheating. I went to drain the radiator, and when I got under the car I found some type of sensor or probe dangling from two wires under the car in front. It is on the driver's side of the vehicle. It is yellow and black in color with the probe (sensor) part being black. To the best of my vision here are the part numbers: Yellow part: 1378403; Black pointed probe: 1383204. Where does this go? And could it be the reason my radiator and engine is overheating? That it needs plugged back in? Thank you in advance for any help.

It goes into the driver's side air intake duct for the brakes. The duct is in the lower valence. I believe this one is the outside air temp sensor.

If your '92 has the original water pump, fan clutch, thermostat, and radiator you need to replace them all. Overheating can be caused by all of these nearing failure.

yeah . mike hit it right on the nose . . .it's your outside temp sensor and goes in your driverside brake duct.

As far as your raditor goes read this and I would check the water pump and thermostat. Early E36 had plastic impellars and they broke off after time so, they tell you to replace them.

http://www.pelicanparts.com/BMW/techarticles/E36-Coolant_Flush/E36-Coolant-Flush.htm

water pump replacement: http://www.pelicanparts.com/BMW/techarticles/E36-Water-Pump/E36-water-pump.htm

Thermostat replacement: http://www.pelicanparts.com/BMW/techarticles/E36-Thermostat/E36-Thermostat.htm