Run down to the local AutoZone and buy the electric fan temp control module. It's about 50 bucks with relay and everything included. This module allows you to control the "on" and "off" without having to get your ECM reprogrammed to change the temp. This is really handy for winter vs. summer driving. In the winter you can have it a bit higher and in the summer or for performance you can change it to super cool with just the twist of a knob.