cooling fan sensors location?

Hi, I just finished repairing my 1998 toyota corolla after a front end collision that deployed both air bags, Replaced rt front fender, hood, radiator support, radiator, condencer and front bumper and all front lights, also both cooling fans. I may not have a problem. The car runs good and the temp gauge moves up to half way on scale and runs at that temp ok. The a/c fan and cooling fans kick on with the air conditioner running, but the cooling fan only has never kicked on. All fuses ok. My question is at what temp dose the radiator cooling fan kick on and where is the sencor located? The ambient temperature is around 25 deg.

Thanks for any help, shopmate250 im guessing. the sensor should b near the theromstat housing?Car Repair Talk's forum.