With the controls set in 'auto' the ac will cycle on and off depending if the computer thinks the windshield needs defrosting. The ac cools air and also removes moisture so it may be cycled on in temperatures as low as 36F to reduce humidity and condensation.

Does the blower really cycle on and off or does it drop to a very low speed?

The automatic control may drop or raise the fan speed depending on the temperature it measures in the cabin. It also increases fan speed if it thinks the windshield needs defrosting.

I tend to use manual controls except for temp. Have had no problems.

mormit
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85 245DL, 02 S40