if we understood you correct, you have aftermarket electric fans installed, one for coolant and one for a/c? because a/c condensor is the only fan i am aware of. unless you have some cute-er set up?
if that's the case, start with checking voltage and amperage supplied to fan when it's running.
next, will be checking the fan itself. fans do go bad, you know.
unless you have clutch fan, like it used to be in the older vehicles, then clutch it getting tired.
or you have g'ol belt driven fan, then belt is stretched.