W140 climate control issues
 

Just bought a '98 S600 sedan. I get in it, it starts right up, and the fan in the rear starts and goes on high, but only blows out cold air. Then the fan up front won't change speed at all. I turned on the climate control in the front, and the only reason that I noticed that the fan was actually turning, was that I live in a very VERY quiet neighborhood and it is very quiet in the car. It is blowing at such a low speed that it is unbelievable. So if anyone can tell me what to do to fix these problems, it would be greatly appreciated!!