Dear Benzmac,

I just had my AC system serviced and filled up with R12, but my aux fan never comes on! I asked them to check the aux fan for proper engine temp and AC operation, and they said it was working fine.

This is on the West coast, where it was about 65 today, but the intense sunshine makes the interior of a dark gray car very toasty. I ran the AC continuously for an hour and when I climbed the hill to my driveway and popped the hood, the aux fan was not on. (But the sight glass was clear with the compressor running, and the air was nice and frigid!)

Under what conditions can I expect to see the aux fan come on?

Thanks! Great site btw.
Justin Dobbs