I just bought a Hypertech Cool Fan Switch (200 on 185 off). I understand that you just put the new fan switch into the olds ones place, but after installing the wiring harness that they give with it to the switch, how do you connect the new harness to your old harness? And should teflon tape be used on the threads or not?

on mine i just used a light sealant like a tube liquid sealer... teflon tape is too thick and i belive the sensors ground themselves through the block through the threads. u have to cut the old connector off and either crimp/soder/or put a quick disconnect connecter for the new connector. i would do the qick disconnecter(since i had 2 diff temp sensors i had to keep cutting the old one off, one style connector would allow easy transfer between 2 diff sensors for different seasons etc winter/sumer).... i had a jet one at 200 on 185 off with a 180 stat and it still got to warm in the summer traffic, so i went with the 176 on 166 off with a 160 stat and i connected my dual fans off of one relay so they both turn on at 176... never had a prob again.

just put the same set up on my car...I used Teflon tape though...I did not put the tape all the way down the sensor so it will still ground. I had to cut and splice my wire too. It is an easy job but a pain to drain the radiator.

Red bird is right, just splice to new connector. Took more time catching and refilling coolant than putting switch and connector in. After putting in, I never had another (running-hot) problem. Best $50 I ever spent at Jegs.

What do you define as too hot?

The way I see it, at 200°, both your fans are on and the thermostat is open. Anything above that would be the same with either of your setups.

160° stat with both fans on at 176° seems like overkill. Terrible mileage and too cold in the winter. Does 176° really mean you need both fans turned on? Heck, my thermostat is still closed and fans are off at that point.

I have the 200/185 fan switch, my chip set to turn the other fan on at 190/185, and a 180 thermostat. It works perfect as far as I can tell. 180 on the highway for best performance, 190 around town with A/C on. 200 when sitting in rush hour traffic going nowhere. Might as well get the better fuel economy and boil out the moisture when you're sitting in traffic stopped.

I saved about $10 and picked up a fan switch from and 87 Buick Grand National(NAPA part number ECHFS113). Turns the fan on at 220 and off at 204 and as side benefit already has thread sealant on it. I threw in a 180 degree thermostat and all is good. The biggest difference in keeping everything cool was when I replaced the fan motor. After 140,xxx miles I guess it was wore out like everthing else.

difference why i run 166 on 176 off. with both fans on is that my one relay blew that controlled the fan so i reached 240/260 on the highway which i never want to see again... lucky i didnt warp the heads. so i connected both fans to one relay which is the way it should be. that was with the 200 on 180 off jet switch and 180tstat... and with the 200/180 jet switch i noticed that my temp stayed around 200 for the most part in the summer if not higher like 210... in NJ the humidity and 100 degrees will destroy a motor. car also runs original modine aluminum 1 core radiator which sucks for cooling. not to mention u also have to worry about increased trans heat due to higher coolant temps (the trans cooler is in the side of the radiator) trans temps were way to hi, my car also tends to run better the cooler it is. when i put the 166/176 stat in and the external trans cooler it mad a huge diff. still gets warm enough for the 02 to kick in, car runs better when its cooler and allows me to make more hp. in the winter its alil rough, and i do drive it alot but i dont try to as much in the winter... firebirds/camaros arent the greatest in the snow.