Assuming you are referring to the Aux fan that is mounted in front of the radiator...headlight side of radiator... then it should be blowing "In" towards the radiator and the engine.

If you have an aftermarket aux fan, I think some of them are wired to be set up as either a pusher or puller fan. You need it set up as a pusher fan (again, pushing air across radiator towards engine).

I would pull the fan and inspect it. With INPA and other good scan tools, you can activate it outside the car. See if you can find a manual or other documentation on the specific fan you have. Maybe you can easily switch wiring on the fan to make it a pusher fan.