Cooling fan relay location

I know every thing sayes the relay for the cooling fan for the radiator indicates it is in the fuse cluster located sort of between the battery and the air cleaner. My problem is when I open the top panel to view the fuses and relays, all I see are the fuses. Can you tell me specifically where this relay is and how to get to it. Also what turns the fan on. I am told it is one of the two sensors near the thermostate. Which one is it, front or back, or what is the color. One is brownish the other is organish, and what is it called.
I really would like to find the relay.