There are three sensors on the housing. One big one with a cylindrical conn. one med size one thats on an angle with a black connector and a flat prong (this is your rad fan switch) and a skiny little one with a small round connector, (thats for your temp guage)
just unplug the connector for the radfanswitch and your fan should come on to low speed, if it doesnt, check the fuse, if thats good check the relays (there are two that could malfunction) the first is one of the 2 relays right around the engine bay fuse box and the other is behind the black cover against your firewall (beside your pwr brake booster)
good luck, peace