1991 Saturn SL1 over heating

Engine Cooling problem
1991 Saturn SL1 4 cyl Front Wheel Drive Manual

please help my car just started boiling over from water tank. I checked it out and noticed that the fans located in front of motor aren't coming on. I ran them direct with a wire to positive post and they run continuiously while I drive until I unhook the wire. Hooking it up as so won't hurt anything will it? So I can fix this correctly where is the sensor for these fans located? Also where is the themastat located? Since the fans work directly hooked up it's not the fans that need replaced right? Thats when I replace the sensor? I checked the fuses. How would I test the fuse to see that it wasn't burnt? Please advice me to fix this issue. I'm a single mother with new baby and teen we need our car. Thank you so very much. E-mail me brandiyounker@att. Net