Put the car in the diagnostics loop by plugging together the two green plugs under your dash. That will cycle all your relays sensors and solenoids, and both fans should cycle on and off.
I would check the relay next (you should hear it click), while in the loop.
If that doesn't get you anywhere, check the sensor which is a bitch to get at. It's under the intake plenum on the cast coolant pipe that goes across the top of the block.
Don't forget to unplug those when you're done. Hope that helps