Ihave a kenmore 70 series, i have heat but for

In the air path between the heater and the dryer drum, and also in the exhaust air path, there are temperature detectors. First thing is to make sure there is good airflow blowing from the dryer exhaust -- not enough airflow will let too much heat build up. Not enough airflow means too much lint somewhere in the exhaust path, or the fan loose on its shaft. If the airflow is good, the one of those temperature detectors is probably dirty or bad.