The fans on my radiators recently have quit on me and no longer turn on when supposed to.. have tested to make sure the fans work by connecting wires from the plugs of the fans to the battery but cannot think of what is initially caused the fans from working.. i've also recently replaced my thermostat with a brand new one. Please help if you know what the problem may be, thanks!

 

A guess would be the cooling fan timer. I think those are located under the passenger seat. little black box. Not sure if yours has one, but those are kinda common for going out. Usually when they go they come on at random times and drain the battery tho. Good luck...

 

You can try taking the wires off of the fan thermo-sensor located on the bottom of the radiator (pass side) and short the blue and black wires. If the fan starts, it's a bad sensor. If not, let me know...we can continue.