Tap the upper radiator housing to fit a 1/8th 180 temp switch in the housing then wire it to switch on the relay.
If you have to keep asking on how to do this and I don't mean to be a douchebag, but seriously, get a fan clutch.  It will be the best cooling setup your can have.  There is no need for an electrical setup when one is as simple as the fan clutch.  You will not have to worry about heating issues in the Summer with the A/C either.  Electric fans will not be able to cope with the added heat during the Summer.  Aftermarket electric fans are not the equivalent to an OEM electric fan setup.