Lately my Marauder had been overheating and the air only worked on extreme low and extreme high (no where in the middle). Today, I changed the thermostat to a 180 degree stat assuming that this would fix the problem. Once I started the car and drove it briefly, it began to overheat again. No heat would circulate although the engine was hot. Does anyone know what else could be wrong? Is there a sensor that could be bad?