I found a picture of your fans here
So I assume they are electric and not belt driven.
I can thing of the following things that may be broken,
1) Blown Fuse
2) Relay Switch Broken
3) Thermostat switch Broken
4) The fan motor is burnt out.
If it is 1) then replace the fuse. If it blows again you probably have a short circuit somewhere. Check the wiring.
There is a description here
about the relay(s) and where to find them in your vehicle
Disconnect the power plug to the fan and run a wire from the positive battery terminal. If it spins up ok then it isn't 4).
That leaves the thermostat switch. I'm not sure how you can test that one. I suppose you could join the two wires together as that is what happens inside the switch when the coolent tempreature gets to around 205F This should turn on the fan.
I have read that the relay is two stage so I'm not sure how the thermostat controls this. Perhaps one fan starts and then the other or the fans are dual speed.
You will have to investigate and follow the wires around to locate all these parts but at least it gives you some ideas and some places to start. It may also help you narrow the field. Post again here with the things you have found and we may be able to help you further. :)