The electric aux fan on my car is in front of the radiator.

In all honesty, though, it might be better to buy an aftermarket fan, and then get the biggest one that you can fit in there. leathermang posted a site where you could get them not too long ago; I don't remember exactly what the URL is, though.

I think that the fan runs off of a sensor on the engine to sense engine temp, but I don't know where this is if that's true, and it's also suposed to come on whenever the a/c compressor is engaged.

I'd love to get mine working, but I need a new brush housing...the front bearing died on mine, and the brushes melted the plastic housing while trying to turn it.