I made this diagram for wiring a slim fan a while ago, but I can't remember if I ever posted it or not. With this method, the factory wiring triggers a relay that supplies 12v directly to the fan, and the ECU controls the fan just like it did in stock form. To do this, cut the black and blue wires going to the fan as close to the fan as you can to give you the most room to work with. Then connect them to the relay as indicated in the diagram. The use of the relay allows a constant steady 12v power supply to the fan, similar to rewiring your fuel pump (read the VFAQ for info on what relay to get). As for the fuse, pick the amperage indicated in the documentation that came with whatever fan you are running. If you want to wire two fans to run at the same time, splice the black and blue wires (the ones that went to the stock fan) and run them to another relay in *PARALLEL* (if you run them in series, both fans will shut off in one fails or a fuse blows). This wiring is specific to 1g cars, as I believe the 2g cars have 4 wires going to the fan instead of 2.
Hope this helps!
