[V]

wire the relay up properly, using a harness for the dual fans, not that hard to find. It has the two relays in it, one comes on at the specified temp and the other comes on as well if the a/c is turned on. The relays/wiring should be intact in the GTA to begin with, just a matter of maybe repairing some wires.

do NOT run a fan on just a switch, especially to the ignition terminal on the fuse block. Not only WILL you overheat and melt the switch, but in many cases, when you turn off the car, it can "diesel" as if its still trying to run. That is caused by the fan going from an electric motor, to basically what you could call a generator. It will then create a small amoutn of voltage and feed it back into the fuse block. Ive seen that in several cases. You asked how to do it right...and thats with one relay PER fan.