faulty sensor one is for turning fan on at correct temp and one is for shutting fan off when not needed,
Turn the AC on and the electric fan on the radiator should run.
The radiator fan sensor switch or the radiator fan motor are at fault (maybe even both). Wire the fan motor direct to see if it will run, if it does, replace the sensor switch. If the fan motor doesn't run, replace the fan motor before you buy a new sensor. If after replacing the fan motor, the fan still doesn't run, then replace the sensor.
no the radiator fan will only run when the engine is up to temp and needs to cool back down usually 180 to 220 degrees
That one should run anytime the a/c is turned on.
Run a hot wire to the positive wire on the radiator fan. If it works, then you have a fuse or a relay (or even a short in the wire). If it doesn't work at all, then the fan motor is bad.
Either your engine is running hot or the fan switch in the radiator has failed or the relay is stuck.
unplug the coolant sensor and turn on the ignition without starting the engine. The fan will run.
a bad fan control relay
The radiator may need to be rodded out. The thermostat could be stuck shut. The sensor for the radiator fan may be bad. The radiator fan itself could be bad.
If the fan that is running is the radiator fan, this is nothing to be concerned with. Some vehicles have fans that will run even if the car is off. The fans run to cool the engine down. If it continues to run, the radiator fluid may need to be replaced. If the fan that is continually running is the heater/air conditioner fan, there is an issue with the switch that turns it on and off, or in the electrical system. This can be checked by a mechanic.
The radiator fan should not run after the key is shut off. The normal cause is a failed radiator fan relay.