I am getting a electric fan tommorow, so I want to figure out how to wire the fan up with my water temp sensor (the one the choke uses) so that the fan will turn on after the car is warmed up to operating temp. I am going to get a 2 speed fan. Is this a good idea or should I just get a 3 position switch and just operate the fan manualy? Thanks in advance.

 

I wired mine so that it comes on (low speed) when the ignition is on, that way there's no guesswork, therefore no danger of it not coming on at the right time when warm. These rotaries are not forgiving of an overheat.
Just my opinion, others have wired it up with a temp sensor and had good luck with it.
I also wired my high speed to come in when I have AC on.

 

You can rig it up using a temp sensor and adjustable thermo switch. That way you can set it to come on at whatever temp you want. That's how I had mine.

Also, stay away from the sensors that place the probe in between the fins of the radiator. Crappy idea if I've ever seen one. You can get ones that go inside the radiator hose that are a lot better.