There are typically several problems contributing to overheating, not just one. However, if it is related to the electric fan, here are a few things to consider...
1. Don't use the engine fan and an electic fan (in front of the radiator) together. The electric fan may actually block or hinder air flow. Electric fans as usually best as puller fans behind the radiator and will typically flow more air this way. Also, make sure the electric fan is mounted as closely to the radiator as possible (usually they're mounted directly to the radiator with those zip-tie things).
2. Make sure it is wired correctly, so that the air is actually being pulled through the radiator. If it doesn't seem to flow enough air, try reversing the wiring.
3. Make sure specs for the fan indicates it flows decent CFM, ideally 2200 or better.
Also, from what I read in you initial post, it sounds like you added the electric fan because the car was overheating before. If that was the case, that usually means there are probably other issues contributing. Make sure the radiator is adequately sized (3 cores minimum for a traditional brass radiator) and isn't clogged. Also make sure there aren't any blockages in cooling system, that your radiator hoses aren't collapsing as the motor revs up, and verify the waterpump is working correctly (and is flowing in the right direction, i.e normal vs. reverse flow). Try using a lower temp thermostat (160 degree is a good starting point). Finally, make sure the motor is tuned correctly (not too much timing advance) and isn't running lean (causing more heat). Remember, its called a cooling
system ... everything has to work together.
Hope that helps. Good luck.