'99 radiator fan won't run

I've just read the other threads on this subject and I would think that a reply on the one from a '98 would work for me, but I can not find the fan relay. It is not located below the airbox as explained on a '98. My temp gauge works fine so I can assume that the temp sending unit is good. The fuse is good and even put a new one in just in case. Replaced the radiator fan assembly, (one motor was bad). Also there is not a temp unit connected to the radiator as explained on the '98.
Can anyone tell me exactly where the relay is on a '99?!

Just thought I'd let you all know that I had to take it to mechanic and it was the sensor. It is located under the front air intake tube, on the frame, but you have to remove the left headlight assembly to get to it! Factory rivets it to the frame.