After driving I parked my car It idled for a few minutes with the air on before I shut it off When I was ready to leave 20 min it wouldn t start I had someone bring cables to jump it It started fine A passerby thought it smelled hot I wasn t steaming or obvious I pulled out and the guage was almost on red I checked fluids and they were all full I drove home 5 miles and the guage never moved The battery posts were corroded bad I don t know which came first the battery or the overheating. I've heard the fan can stick also. Should I get a battery or take it in?