Welcome to JustAnswer, my name is XXXXX XXXXX I'm here to help get your problem solved. Here is a wire diagram and description of how system works. Unplug the temperature sensor in the bottom of the radiator and verify the fans come on. If the fans operate, the circuit is OK. Measure the temperature of the radiator at the temperature sensor. The temperature needs to be 195 degrees or higher for the fan switch to open and the fans turn on. If the radiator is not hot enough check the radiator and thermostat. If the sensor at the bottom of the radiator is unplugged, and the fans come on, the circuit is okay. The only answer can be a faulty sensor or no heat to the sensor from a clogged radiator. Let me know if you have questions, thanks.
I unplugged it and they still don't come on even with the a/c on
some one jerry rigged the ecu-ig fuse . they had a small piece of wire wraped around the terminals so it would test good. but if you wiggled it the fans came one. new fuse fixed it. I repaired the fuse hols
der in the fuse box also. thanks for the schematics
thanks for the wiring diag. I used to do elec in the dealerships.