toggle switch to my electric fan

This question is a little off topic, I am wanting to install a toggle switch to my electric fan on my car, I am unsure how things get connected, Cause on the switch has on 2 screw terminals, I am guessing its like looping it. Power in  / power out ?e4

Normally there are three wires to the fan, some have four. You will have a ground, 12 power, and a signal wire. The forth one is either used as a data cable to read the rpms, or used for the sending unit like a thermister, or sending device. Find the wire that activates the fan when grounded. I would suggest that you use a standard sealed SPDT 30 amp relay to actually turn on-off the fan. Regards EVIL Teken . . .

Well on my fan their is only 2 wires power and ground, The reason why I am wanting to use a switch source is on my Mustang the relay is weak and Then I got more control of keeping my temp cooler , Least if I got a fuse link to the switch, I think the fan should be ok.e4

If you wish to keep your Mustang cooler, and obtain a few additional HP. I would suggest that you replace the thermostat with a cooler one, which will open sooner. If you still want to use a switch, then simply wire the switch in series to the ground wire. Remember, you will turning the fan using only a ground plane. That is the safest method for in cabin use. Regards EVIL Teken . . .

Hey now i will go with what Teken said about the switch and also i was wondering how cold u want your car running at cause if u run it to cold u not gonna get a good running condition. what does yours take 192 degress 180 how cool u going to and why u want to run colder then it is Thanks and Have Fun

Well Ive replacedthe fan relay , Temp sending unit, Ive been told my other mechanics this is a common thing to have happen. Unfortunally that year ford didnt do a good job with that part of the car, If I allow the temp to climb to over heat temp, then my engine and alum cyl heads get wrecked so, I would rather have control of my fan from a switch. e4