Chevrolet Repair: Heater Fan, coolant temp, chevy cavalier

Question
My daughter has a 99 Chevy Cavalier and the cooling fan does not shut off.  She took it to a repair place and they put a new thermostat in it because it was overheating and now the fan does not shut off, they can't figure out why.  Do you know?

Answer
Hi Carol, This could be many things and without starting at step one I have no idea what to tell you. I have never seen this before. Here are some possibilities, the engine coolant temp sensor reading very hot, the fan relay stuck on, bad computer, grounded out wiring. Sorry i can't help more, but this is one I need to see to give you a answer.

       Have a Great Day     Mark