Two questions, 1st Heat/AC blower fan. 2nd, Temp gauge. Please see detail

1st, If you vehicle is equipped with automatic Climate Control (you set the temp digitally and the fan automatically adjusts)the speed is controlled by a blower speed control module. This could be the problem, or the climate control head or temp sensor could be commanding the fan to falsely run high all the time. Would recommend to take somewhere that has factory diagnosis scan tools to communicate to the BCM to identify the failure. 2nd, Temp gauge jumping from hot to cold and a smell of coolant sounds like a low cooling system that is boiling, when system is cool recommend to verify proper level. If level is good it could be a circulation problem. Again recommend to have a diagnosis performed, not a straight forward symptom. If you have any further questions please feel free to give us a call or stop by to visit. Your Curt's Service Team 248-545-0500