1998 Catera Cooling System Problem Electrical

I have a 1998 Cadillac Catera (130k MI v6) and the cooling fan on the radiator is not working. The 30AMP fuse (under the hood) for the fan keeps blowing. I have jumped the fan to a 12v source and the fan itself is operational. Does anyone know the location of the temprature switch and/or a testing sequence to diagnose this problem?

Thanks