I just bought a '98 S70. After about 45 min. of driving the fan would slow to a trickle in AUTO, and not work manually. Also would get a roaring noise from the fan after turning AC off then back on. I joined All Data and found what might be a fix. There is a procedure that resets the damper motors that seems to have fixed my problem. With car not running,turn ignition key to position II. Immediately ( within 3 secs ) press the recircularion button 3 times. Wait 30 secs and turn key off. I hope it works for you. As of 5 days after doing this, my S70 has not faltered.