First off, when setting the temp switch for the fans, do it before the thermo outlet. all water post thermo has heat from the turbo cooling lines, therefor is not a very accurate representation of what actual h2o temp is.
second, get a true fan controller. I got one made by SPAL (see the cooling review for a quick overview, see
http://www.spa-usal.com for the real thing). its called the fan-pwm. I have some pics of my install and the user giude @
http://www.gotdiceracing.com/blog
The point of doing things the way i did was two fold:
1. minimize the hit on the electrical system when the fans kicked on. big cooling fans will draw 20-30 amps, no problem. with you lights and heater on, sitting in traffic at idle, having an extra 20-30 amps in overhead in your electrical system doesn't sound realistic.
2. more stable temps. as temp increases, so does the speed of the fan. this is nice to keep things from getting too hot (or too cold) too fast. Keeps the computer from making large tuning adjustments and helps fuel econ.
best part, this can work with their sender or the stock efi temp switch (you'll need some type of temp gauge if you want to mess with the turn-on/ off temps)
Some may disagree and that's ok, but since i installed this fan controller, its a rare day for my fans to ever come on full blast (minimizing wear on the electrical components). My temps run between 180-190 pending what type of driving i do (i have a 195 ford thermostat. PM me for more info on that:sonic: ) with a stock replacement rad.