Fan speeds

[rodbaxter]

I have a '95 E320. I have replaced the thermostat, citrus flushed and refilled with MB coolant and replaced the mono valve. Now I have heat, but the AUTO fan selection won't ever come off the high (noisy) speed.

Is the fan supposed to slowly go down as the heat in the cabin reaches the desired temp? I end up running it on LOW a lot to keep the noise level down and then don't get quite enough heat. It's -18C outside today.

Maybe there is a sensor to check/replace. Any ideas?

[Jackd]

The fan is supposed to slow down in speed when the desired temperature is reached.
I have experiences very low temp (down to -42 last winter) and the fan speed was still on high speed, even though it felt comfortable in the car.
Interior air is draw from up-close to the cold windshield (besides the rear view mirror),and goes inside a plastic tube running under the dash behind the glove box.
If these components are still cold , and even if the interior air feel warm enough, the fan will keep on going full blast for a while until it warms up to the set temperature on your control panel.

[rodbaxter]

That's just it, it never goes down in speed. Even when the temp outside is warmer than today, it never goes off high.

[bryanm]

You interior temp. sensor may be defective.

Use the diagnotic mode to see what temp. the climate control system thinks it is (see CLK 430 Problem)