The car only runs hot when it is over 80 degrees out with high humidity. If I drive on the highway, it cools down, if I drive with AC on it cools down. I explained the problem to a tech and he suggested that there is a switch that went bad (which I have an new one of and have not replaced yet). The part is a Cylinder that has a 1/2" screw in post on one side and 3 contacts on the other. Should I replace this? Is this something that I can do myself, or should I have it done? Where does it go? THANKS FOR YOUR HELP I APPRECIATE IT.