i know in my case that the a/c worked ok without the fan until i had to stop in traffic, then the a/c couldnt keep up, thats when it really needs the fan to keep air circulating at slow and stopped situations.

from my experience as soon as the a/c clutch engages the fan also starts up.

i have a problem where the a/c wont kick in till the car has been in motion for a few minutes, and while my electric fan is good, just replaced it, it wont start until the a/c clutch engages also, so somehow they are interconnected