i just purchased a 1980 280zx. the fan doesn't blow anything but when the temperature slide is pushed to heat i can hear a buzzing (heater core maybe?). i am using this car as a daily driver now and the fog on the interior glass is not only annoying it is dangerous. the leaking t-tops don't help the moisture problem in the least. need some input on how to economically remedy the situation. this is my first z and i do not know very much about the car, so i do not know what to check. garaging the car is not an option this season so any input would be greatly appreciated. i have fallen in love with this car and plan on bringing it back to its original glory, but one step at a time.help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!