crazy climate control

The thermometer on my 95 Aurora has gone crazy. It registers 123 degrees which means it doesn't want to heat and tries to cool even during the winter. Has anyonhe had this problem? What is the fix?
Thanks.

I don't know how to fix it but the thermometer sensor is behind the front bumper below the radiator. You could check to make sure it is plugged in right and there are no broken wires.

Just cleaning it well makes a big difference.

Thanks for the advice. The thermometer sensor had gotten unplugged and against the radiator.