Climate Control Problem-Ideas Please
 

I’m interested in opinions on what might be the problem. I have a 1995 SL 600. The climate control is exhibiting the following symptoms:

1.diagnostics show no faults;
2. the three strip fuses look fine;
3. the fan operates at only one speed;
4. fan speed doesn’t change when pushing the buttons for different fan speeds;
5. the air coming out of the vents is sometimes hot, and sometimes cool no matter what the temperature setting is, and when it is hot or cold seems random;
6. the only way I can get A/C air into the passenger compartment is to press the blue button on the center dash vents and close the side vents;
7. when under acceleration, no air is blown into the passenger area through the vents. Once speed stabilizes then air again begins blowing into the passenger area.

Any thoughts on what might be the problem or problems?

Thanks.